Word Origin & History
thorn
O.E. þorn "sharp point on a stem or branch," earlier "thorny tree or plant," from P.Gmc. *thurnuz (cf. O.S. thorn, Du. doorn, O.H.G. dorn, Ger. Dorn, O.N. þorn, Goth. þaurnus), from PIE *trnus (cf. O.C.S. trunu "thorn," Skt. trnam "blade of grass," Gk. ternax "stalk of the cactus," Ir. trainin "blade of grass"), from *(s)ter-n- "thorny plant," from base *ster- "stiff." Fig. sense of "anything which causes pain" is recorded from c.1230 (thorn in the flesh is from II Cor. xii.7). Also an O.E. and Icelandic runic letter (þ), named for the word of which it was the initial. Thorny is O.E. þornig; fig. sense is attested from c.1340.