The first two levels of the WordNet 1.5 ontology of noun meanings
WordNet is a public domain on-line lexical reference system developed at Princeton University. In version 1.5, some 120,000 word forms of English nouns, verbs, adjectives and adverbs are connected to approximately 91,600 synonym sets (synsets), each representing an underlying lexical concept, that is, a word meaning (each synset is unique, all synsets are disjoint). The synsets which include (and then express the meaning of) nouns or verbs are connected by semantic relations such like IsA, Part-of, Cause-of and Attribute. The synsets for nouns are not organised with the synsets for verbs. However, these last synsets are not very well structured by relations of specialisation (more exactly, there is a long and unstructured list of top-level synsets for verb meanings). The synsets for nouns refering to actions are much more structured than synsets for verbs. So, here we only present the top-level synsets for noun meanings. Here are the 10 uppermost categories (synsets) for noun meanings and their direct sub-categories according to the IsA relation. entity -- (something having concrete existence; living or nonliving) => life form, organism, being, living thing -- (any living entity) => cell -- (the basic structural and functional unit of all organisms; ...) => causal agent, cause, causal agency -- (any entity that causes events to happen) => object, inanimate object, physical object -- (a nonliving entity) => thing -- (an entity that is not named specifically; "I couldn't tell what the thing was") => whole, whole thing, unit -- (an assemblage of parts that is regarded as a single entity; ...) => subject, content, depicted object -- (something selected by an artist for graphic representation) => unit, building block -- (a single undivided natural entity occurring in the composition of something else) => part, piece -- (a portion of a natural object) => necessity, essential, requirement, requisite, necessary, need -- (anything indispensible that is needed; ...) => inessential -- (anything that is not essential) => variable -- (something that is likely to vary; something that is subject to variation; ...) => anticipation -- (some early entity whose type or style anticipates a later one; ...) location -- (a point or extent in space) => home -- (the country or state or city where you live; ...) => earth -- (the abode of mortals (as contrasted with heaven or hell)) => imaginary place -- (a place said to exist in religious or fictional writings) => line -- (a spatial location defined by a real or imaginary unidimensional extent) => point -- (the precise location of something; "she walked to a point where she could survey the whole street") => region, part -- (the extended spatial location of something; "the farming regions of France"; ...) => region -- (a large indefinite location on the surface of the earth) => whereabouts -- (the general location where something is; ...) => pass, mountain pass, notch -- (the location in mountains that is lower than the surrounding peaks) abstraction -- (a concept formed by extracting common features from examples) => time -- (the continuum of experience in which events pass from the future through the present to the past) => space -- (the unlimited 3-dimensional expanse in which everything is located) => attribute -- (an abstraction belonging to or characteristic of an entity) => relation -- (an abstraction belonging to or characteristic of two entities or parts together) => measure, quantity, amount, quantum -- (how much there is of anything) => set -- (an abstract collection of numbers or symbols; "the set of prime numbers is infinite") group, grouping -- (any number of entities (members) considered as a unit) => arrangement -- (an orderly grouping (of things or persons)) => kingdom -- (a basic group of natural objects) => biological group -- (a group of plants or animals) => world, human race, humanity, humankind, mankind, man -- (all of the inhabitants of the earth; ...) => people -- (any group of persons (men or women or children) collectively; ...) => social group -- (people sharing some social relation) => collection, aggregation, accumulation, assemblage -- (several things grouped together) => edition -- (all of the identical copies of something offered to the public at the same time; ...) => ethnic group, ethnos -- (people of the same race or nationality who share a distinctive culture) => race -- (people who are believed to belong to the same genetic stock) => subgroup -- (a distinct and often subordinate group within a group) => sainthood -- (saints collectively) => citizenry, people -- (the body of citizens of a state or country; "the Spanish people") => population -- (a group of organisms of the same species populating a given area; ...) => multitude, masses, mass, hoi polloi, people -- (the common people generally; ...) => system -- (a group of interrelated elements comprising a unified whole) possession -- (anything owned or possessed) => ownership -- (possession with the right to transfer possession to others) => property, belonging, holding, material possession -- (any tangible possession that is owned by someone) => territory, dominion, territorial dominion, province, mandate, colony -- (a territorial possession ...) => white elephant -- (a valuable possession whole upkeep is expensive) => transferred property, transferred possession -- (a possession whose ownership changes or lapses) => asset -- (anything of material value or usefulness) => liability, financial obligation, indebtedness, pecuniary obligation -- (possession owed to someone else) state -- (the way something is with respect to its main attributes; ...) => skillfulness -- (the state of being skillful) => cognitive state, state of mind -- (the state of a person's cognitive processes) => medium -- (a state that is intermediate between extremes; a middle position; "a happy medium") => condition -- (a mode of being or form of existence of a person or things: "the human condition") => condition, status -- (a condition or state at a particular time: "a condition (or state) of disrepair"; ...) => situation, state of affairs -- (the general state of things; the combination of circumstances at a given time;...) => relationship -- (a state of connectedness between people (especially an emotional connection); ...) => relationship -- (a state involving mutual dealings between people or parties or countries) => utopia -- (ideally perfect state esp in its social and political and moral aspects) => dystopia -- (state in which the condition of life is extremely bad as from deprivation or oppression or terror) => nature, wild, natural state, state of nature -- (a wild primitive state untounched by civilization; ...) => isomerism -- (the state of being an isomer; ...) => degree, level, stage, point -- (a specific identifiable position in a continuum or series or esp in a process; ...) => office, power -- ((of a government or government official) holding an office means being in power; ...) => status, position -- (the relative position or standing of things or esp persons in a society, ...) => being, beingness, existence -- (the state or fact of existing: "a point of view gradually coming into being";...) => nonbeing => employment -- (the state of being employed or having a job) => unemployment -- (the state of being unemployed or not having a job: ...) => order -- (established customary state esp. of society; "order ruled in the streets"; "law and order") => disorder -- (a disturbance of the peace or of public order) => hostility, enmity, antagonism -- (a state of deep-seated ill-will) => illumination -- (the degree of visibility of your environment) => emotional state, spirit -- (the state of a person's emotions (especially with regard to pleasure or dejection);... => freedom -- (the condition of being free; the power to act or speak without externally imposed restraints) => representation, delegacy, agency -- (the state of serving as an official and authorized delegate or agent) => dependence, dependance, dependency -- (lack of independence or self-sufficiency) => motion -- (a state of change; "they were in a state of steady motion") => motionlessness, stillness => dead letter, non-issue -- (the state of something that has outlived its relevance) => action, activity, activeness -- (the state of being active; "his sphere of action"; "volcanic activity") => inaction, inactivity, inactiveness -- (the state of being inactive) => temporary state => imminence, imminency, impendence, impendency, forthcomingness -- (... liable to happen soon) => readiness, preparedness -- (the state of being ready or prepared for use or action esp military action:...) => union -- (the state of being united) => maturity, matureness -- (state of being mature; full development) => immaturity, immatureness -- (not having reached maturity) => grace, state of grace -- (a state of sanctification by God) => omniscience -- (the state of being omniscient; having infinite knowledge) => omnipotence -- (the state of being omnipotent; having unlimited power) => perfection, flawlessness, ne plus ultra => integrity, unity, wholeness -- (an unreduced or unbroken completeness or totality) => imperfection, imperfectness -- (the state or an instance of being imperfect) => receivership -- (the state of property that is in the hands of a receiver; "the business is in receivership") => state of matter -- (gases and liquids and solids are the three traditional states of matter) => end, destruction, death -- (a final state; "he came to a bad end"; ...) psychological feature -- (a feature of the mental life of a living organism) => cognition, knowledge -- (the psychological result of perception and learning and reasoning) => motivation, motive, need -- (the psychological feature that arouses an organism to action) => feeling -- (the psychological feature of experiencing affective and emotional states) act, human action, human activity -- (something that people do or cause to happen) => action -- (something done (usually as opposed to something said); ...) => nonaccomplishment, nonachievement -- (an act that does not achieve its intended goal) => rejection -- (the act of rejecting something; "his proposals were met with rejection") => activity -- (any specific activity or pursuit; "they avoided all recreational activity") => judgment, judgement, assessment -- (the act of judging or assessing; ...) => production -- (the act of producing something) => stay -- (continuing or remaining in a place; "they had a nice stay in Paris") => residency, residence, abidance -- (the act of dwelling in a place) => inactivity -- (being inactive) => hindrance, interference -- (the act of hindering or obstructing or impeding) => stop, stoppage -- (the act of stopping something; "the third baseman made some remarkable stops") => group action -- (action taken by a group of people) => communication, communicating -- (the activity of communicating) => speech act -- (the use of speech to perform some act) event -- (something that happens at a given place and time) => might-have-been -- (an event that could have occurred but never did) => nonevent -- (an anticipated event that turns out to be far less significant than was expected) => happening, occurrence, natural event -- (an event that happens) => social event -- (an event characteristic of persons forming groups) => miracle -- (a marvellous event manifesting a supernatural act of God) => Fall -- (the lapse of mankind into sinfulness because of the sin of Adam and Eve; ...) phenomenon -- (any state or process known through the senses rather than by intuition or reasoning) => natural phenomenon, nature -- (all non-artificial phenomena) => levitation -- (the phenomenon of a person or thing rising into the air by apparently supernatural means) => metempsychosis, rebirth -- (after death the soul begins a new cycle of existence in another body) => consequence, effect, outcome, result, upshot -- (a phenomenon that is caused by a previous phenomenon) => luck, fortune, chance, hazard -- (an unknown and unpredictable natural phenomenon ...) => luck, fortune -- (an unknown and unpredictable natural phenomenon that leads to a favorable outcome) => act of God, force majeure, vis major, inevitable accident, unavoidable casualty -- (an extraordinary ...) => process -- (a sustained phenomenon or one marked by gradual changes; ...)