Old English ilca "the same" (pron.), from Proto-Germanic *ij-lik (compare German eilen), in which the first element is from the PIE demonstrative particle *i- (see yon) and the second is that in Old English -lic "form" (see like (adj.)). Of similar formation are each, which and such, but this word disappeared except in Scottish and thus did not undergo the usual southern sound changes. Phrase of that ilk implies coincidence of name and estate, as in Lundie of Lundie; it was applied usually to families, so that by c. 1790 ilk began to be used with the meaning "family," then broadening to "type, sort."
updated on October 11, 2015