The linguistic branch of semiotics. http://en.wikipedia.org/wiki/Semantics
A partial description here:
Semantics is the study of meaning in communication. The word derives from Greek σημαντικός (semantikous), "significant", from σημαίνω (semaino), "to signify, to indicate" and that from σήμα (sema), "sign, mark, token". In linguistics it is the study of interpretation of signs as used by agents or communities within particular circumstances and contexts. It has related meanings in several other fields.
Semanticists differ on what constitutes meaning in an expression. For example, in the sentence, "John loves a bagel", the word bagel may refer to the object itself, which is its literal meaning or denotation, but it may also refer to many other figurative associations, such as how it meets John's hunger, etc., which may be its connotation. Traditionally, the formal semantic view restricts semantics to its literal meaning, and relegates all figurative associations to pragmatics, but this distinction is difficult to defend. The degree to which a theorist subscribes to the literal-figurative distinction decreases as one moves from the formal semantic, semiotic, pragmatic, to the cognitive semantic traditions.
The word semantic in its modern sense is considered to have first appeared in French as sémantique in Michel Bréal's 1897 book, Essai de sémantique'. In International Scientific Vocabulary semantics is also called semasiology. The discipline of Semantics is distinct from Alfred Korzybski's General Semantics, which is a system for looking at non-immediate, or abstract meanings.