Sememe

A sememe () is a semantic language unit of meaning, analogous to a morpheme. The concept is relevant in structural semiotics.
A sememe is a proposed unit of transmitted or intended meaning; it is atomic or indivisible. A sememe can be the meaning expressed by a morpheme, such as the English pluralizing morpheme "-s", which carries the sememic feature [+ plural]. Alternatively, a single sememe (for example [go] or [move]) can be conceived as the abstract representation of such verbs as "skate, roll, jump, slide, turn", or "boogie". It can be thought of as the semantic counterpart to any of the following: a meme in a culture, a gene in a genome, or an atom (or, more specifically, an elementary particle) in a substance. A seme is the name for the smallest unit of meaning recognized in semantics, referring to a single characteristic of a sememe.
There are five types of sememes: two denotational and three connotational, the latter occurring only in phrase units (they do not reflect the denotation):
The operational definition of synonymy depends on the distinctions between these classes of sememes. For example, the differentiation between what some academics call cognitive synonyms and near-synonyms depends on these differences.
A related concept is that of the "episememe" (as described in the works of Leonard Bloomfield), which is a unit of meaning corresponding to the tagmeme.