
They could be observed from top to bottom, where the higher level is more general and the lower level is more specific. The hierarchical structure of semantic fields can be mostly seen in hyponymy. A word can be both a hypernym and a hyponym: for example purple is a hyponym of color but itself is a hypernym of the broad spectrum of shades of purple between the range of crimson and violet. For example, violet is a hyponym of purple and purple is a hyponym of color therefore violet is a hyponym of color. 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 instance, the word screwdriver used in the previous example refers to the screwdriver tool, and not to the screwdriver drink. 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 example, "A screwdriver is a kind of tool" makes sense, but not "A tool is a kind of screwdriver". 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, verbs such as stare, gaze, view and peer can also be considered hyponyms of the verb look, which is their hypernym. Like nouns, hypernyms in verbs are words that refer to a broad category of actions. While hyponyms are typically used to refer to nouns, it can also be used on other parts of speech. This, however, becomes more difficult with abstract words such as imagine, understand and knowledge. An approach to the relationship between hyponyms and hypernyms is to view a hypernym as consisting of hyponyms.

The semantic field of a hypernym, also known as a superordinate, is broader than that of a hyponym. A hyponym is a word or phrase whose semantic field is more specific than its hypernym. Hyponymy shows the relationship between a generic term (hypernym) and a specific instance of it (hyponym).
