lexical item
Definition - (Aka lexeme | lexical unit)

A set of words that has the same base form.

For example, run, runs, ran and running are all members of the same lexical item; the base form is run.

Oxford English Dictionary -
The term's first citation is from 1964:
"Archaic features may be preserved in different lexical items in different places."
(R. A. Hall Introd. Ling. liii. 254)

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