1610s as a term in logic; general sense of "being the same or very similar" is from 1630s, from Medieval Latin identicus "the same," from Late Latin identitas "identity, sameness," ultimately from combining form of Latin idem "the same" (see idem). Replaced Middle English idemptical (late 15c.), from Medieval Latin idemptitas "identity," from Latin idem. Related: Identically.
this is the identical room we stayed in before
cars identical except for their license plates
rows of identical houses
identical twins are monovular
identical triangles
ideally
ideate
ideation
idem
idempotent
identical
identifiable
identification
identifier
identify
identity