A unit of semantic structure conventionally associated with a linguistic form central to LCCM theory. Together, a lexical concept and a form make up a linguistic unit : a conventional form-meaning pairing. Lexical concepts constitute linguistically encoded concepts – that is conceptual knowledge encoded in a form that can be externalized via language.

Lexical concepts are conventionally associated with linguistic forms of all kinds including words, bound morphemes, idiomatic expressions and grammatical constructions. Accordingly, lexical concepts, by definition, concern purely linguistic knowledge, although a given lexical concept provides access to a cognitive model profile and thus serves as an access site to encyclopedic knowledge which is deployed in the service of building a conception. There are a number of properties associated with lexical concepts, perhaps the most important of which is that each lexical concept has a unique lexical profile. Examples of four distinct lexical concepts encoded by the form fly are illustrated by the examples below. Lexical concepts are glossed by small capitals in square brackets.

1. The plane/bird is flying (self-propelled (in the sky) aerodynamic motion)
2. The pilot is flying the (operation of entity plane (in the sky) capable of aerody namic motion)
3. The child is flying the (control of light kite (in the breeze) weight entity)
4. The flag is flying (in the (suspension of light breeze) weight object)