Define
late Middle English: from Old French ethimologie, via Latin from Greek etumologia, from etumologos ‘student of etymology’, from etumon, neuter singular of etumos ‘true’.
wiktionary
From Middle English definen, from Old French definer, variant of definir, from Latin dēfīniō(“limit, settle, define”), from dē + fīniō(“set a limit, bound, end”)
etymonline
define (v.)
late 14c., deffinen, diffinen, "to specify; to fix or establish authoritatively;" of words, phrases, etc., "state the signification of, explain what is meant by, describe in detail," from Old French defenir, definir "to finish, conclude, come to an end; bring to an end; define, determine with precision," and directly from Medieval Latin diffinire, definire, from Latin definire "to limit, determine, explain," from de "completely" (see de-) + finire "to bound, limit," from finis "boundary, end" (see finish (v.)). From c. 1400 as "determine, declare, or mark the limit of." Related: Defined; defining.
