In linguistics, a hyponym
is a word that can be changed with a different and less precise word
without changing the overall meaning of the phrase. The different word
is its hyperonym, hypernym or superordinate term. Hyponymy
is a relation to a more generic word. A hyponym can be part of a group
of words on a similar level that can all be replaced by the same
hypernym. For example, pigeon, crow, eagle and seagull are all hyponyms (co-hyponyms) of bird (their hypernym). In turn, bird is a hyponym of animal. In a sentence such as 'The pigeon is flying over the church.', it is possible to change the word pigeon to bird or animal without changing the overall meaning of the sentence. This is because pigeon is a hyponym of both bird and animal.
Hyponymy shows the relationship between a generic term (hypernym) and
a specific instance of it (hyponym). A hyponym is a word or phrase
whose semantic field is more specific than its hypernym. The semantic
field of a hypernym, also known as a superordinate, is broader than that
of a hyponym. An approach to the relationship between hyponyms and
hypernyms is to view a hypernym as consisting of hyponyms. This,
however, becomes more difficult with abstract words such as imagine, understand and knowledge.
While hyponyms are typically used to refer to nouns, it can also be
used on other parts of speech. Like nouns, hypernyms in verbs are words
that refer to a broad category of actions. For example, verbs such as stare, gaze, view and peer can also be considered hyponyms of the verb look, which is their hypernym.
Hypernyms and hyponyms are asymmetric. Hyponymy can be tested by
substituting X and Y in the sentence ‘X is a kind of Y’ and determining
if it makes sense. For example, ‘A screwdriver is a kind of tool’ makes sense, but not ‘A tool is a kind of screwdriver’.
Strictly speaking, the meaning relation between hyponyms and
hypernyms applies to lexical items of the same word class (or parts of
speech), and holds between senses rather than words. For instance, the word screwdriver used in the previous example refers to the tool for turning a screw, and not to the drink made with vodka and orange juice.
Hyponymy is a transitive relation, if X is a hyponym of Y, and Y is a hyponym of Z, then X is a hyponym of Z. For example, violet is a hyponym of purple and purple is a hyponym of color; therefore violet is a hyponym of color. A word can be both a hypernym and a hyponym: for example purple is a hyponym of colour but itself is a hypernym of the broad spectrum of shades of purple between the range of crimson and violet.
The hierarchical structure of semantic fields can be mostly seen
in hyponymy. They could be observed from top to bottom, where the higher
level is more general and the lower level is more specific. For
example, living things will be the highest level followed by plants and animals, and the lowest level may comprise dog, cat and wolf.
