Semantics is the study of meaning in communication. The word derives from Greek σημαντικός (semantikos), "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.

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.

Linguistics

In linguistics, semantics is the subfield that is devoted to the study of meaning, as inherent at the levels of words, phrases, sentences, and even larger units of discourse (referred to as texts). The basic area of study is the meaning of signs, and the study of relations between different linguistic units: homonymy, synonymy, antonymy, polysemy, paronyms, hypernymy, hyponymy, meronymy, metonymy, holonymy, exocentricity / endocentricity, linguistic compounds. A key concern is how meaning attaches to larger chunks of text, possibly as a result of the composition from smaller units of meaning. Traditionally, semantics has included the study of connotative sense and denotative reference, truth conditions, argument structure, thematic roles, discourse analysis, and the linkage of all of these to syntax.

Formal semanticists are concerned with the modeling of meaning in terms of the semantics of logic. Thus the sentence John loves a bagel above can be broken down into its constituents (signs), of which the unit loves may serve as both syntactic and semantic head.

In the late 1960s, Richard Montague proposed a system for defining semantic entries in the lexicon in terms of lambda calculus. Thus, the syntactic parse of the sentence above would now indicate loves as the head, and its entry in the lexicon would point to the arguments as the agent, John, and the object, bagel, with a special role for the article "a" (which Montague called a quantifier). This resulted in the sentence being associated with the logical predicate loves (John, bagel), thus linking semantics to categorial grammar models of syntax. The logical predicate thus obtained would be elaborated further, e.g. using truth theory models, which ultimately relate meanings to a set of Tarskiian universals, which may lie outside the logic. The notion of such meaning atoms or primitives are basic to the language of thought hypothesis from the 70s.