O.E. spir "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