Semantics

Semantics is the name for the scientific study of the meaning of words and sentences.  Semantics is closely associated with the disciplines of linguistics, logic, and philosophy. 

One aspect of word meaning involves the ways words can be semantically related to other words.  Examples of semantic relations include synonymy, or sameness (big-large); antonymy, or opposites (big-little); hyponymy, or subclass (rose-flower); and part-whole (handle-cup).  Another aspect of word meaning is polysemy, the property of having many meanings.  Foot and head, for example, are words with multiple meanings.  The meanings of words change over time.  Historical semantics is the study of these changes.  For example, deer once referred to animals in general, and starve once meant die. 

 Formal semantics, which comes from philosophy, is concerned with truth conditions -- the view that to know the meaning of a sentence is to know all situations and conditions under which it is true.