O.E.
ilca "same" (n. and adj.), probably from demonstrative particle
i- (cognate with Goth.
is "he" and first element of L.
idem) +
-lic "form" (see
like). Of similar formation are
which and
such. Phrase
of that ilk implies coincidence of name and estate, as in
Lundie of Lundie; applied usually to families, so by c.1790 it began to be used with meaning "family," then broadening to "type, sort."
[ilk] 
