One of a Kind
Kind [(kahynd)]"class, sort, variety," from O.E. gecynd "kind, nature, race," related to cynn "family" (see kin), from P.Gmc. *gakundiz (see kind (adj.)). Ælfric's rendition of "the Book of Genesis" into O.E. came out gecyndboc. The prefix disappeared 1150-1250. No exact cognates beyond Eng., but it corresponds to adj. endings such as Goth -kunds, O.H.G. -kund. Also as a suffix (mankind, etc.). Other earlier, now obs., senses in Eng. included "character, quality derived from birth" and "manner or way natural or proper to anyone." Use in phrase a kind of (1591) led to colloquial extension as adv. (1804) in phrases such as kind of stupid ("a kind of stupid (person)").