"sprout, shoot, stalk of grass," from P.Gmc. *spiraz
(cf. O.N. spira
"a stalk, slender tree," M.L.G. spir
"a small point or top"), from PIE *spei-
"sharp point" (see spike
(n.1)). Meaning "tapering top of a tower or steeple" first recorded 1590s (a sense attested in M.L.G. since late 14c. and also found in the Scandinavian cognates). The verb is first recorded early 14c.