Lecture semantic classification of words

Perfect homonyms are words identical both in spelling and in sound-form but different in meaning, e.g. case¹ (n) — ’something that has happened’ and case² (n) — ‘a box, a container’.
Hyponymy is a semantic relationship of inclusion. Thus, e.g. vehicle includes car, bus, taxi and so on; oak implies tree; horse entails animal; table entails furniture. The more general term is called the hyperonym or the classifier, the more specific term is called the hyponym of the more general term.
Synonymy is the semantic phenomenon of closeness in the meanings and the same part-of-speech reference of two or more lexical units.
Synonyms are words different in sound-form but similar in their denotational meaning or meanings and interchangeable at least in some contexts. Synonyms are classified as stylistic, contextual, occasional, etc.