Linguistic Library (Mike Green)

The technical term for a single base unit of independent meaning such as a word, especially a word in its 'base form' as found as a head word in a dictionary's pages shown in bold, e.g. interest, bridge, mouse but also including some 'phrasal verbs' that have separate meanings from their constituent lexemes, e.g. 'to see to', 'to break down', 'to put up with', 'to wind up'.

The collection of lexemes that forms your vocabulary is called your personal lexicon. A dictionary is another kind of lexicon.

Lexical verbs tell of an action (to hit, to call, to sing)

Stative verbs tell of a state of being (to be - am, is, was, were - to think, hope, seem, appear, feel, etc.).

Lexical choice means nothing more than word choice. It's clearly an important aspect of creating a suitable style or register (i.e. when making language choices suited to a particular genre, context, audience and purpose). It might be easier to think of lexis as referring only to the form of a word - its shape and sound as opposed to its content or meaning. So a text containing many polysyllabic word choices, for example, would suggest it is suited for a more educated or older speaker; another example, rhymed word choices might suggest a text written in a style suitable for a younger child, and so on.

Referring to the study or ways of language and the use of words to create meaning.