n. [ L. pinnula, dim. of pinna feather: cf. F. pinnule. ] 1. (Bot.) One of the small divisions of a decompound frond or leaf. See Illust. of Bipinnate leaf, under Bipinnate. [ 1913 Webster ]

2. (Zool.) Any one of a series of small, slender organs, or parts, when arranged in rows so as to have a plumelike appearance; as, a pinnule of a gorgonia; the pinnules of a crinoid. [ 1913 Webster ]

v. t. [ imp. & p. p. Pinnacled p. pr. & vb. n. Pinnacling ] To build or furnish with a pinnacle or pinnacles. T. Warton. [ 1913 Webster ]

n. [ OE. pinacle, F. pinacle, L. pinnaculum, fr. pinna pinnacle, feather. See Pin a peg. ] 1. (Arch.) An architectural member, upright, and generally ending in a small spire, -- used to finish a buttress, to constitute a part in a proportion, as where pinnacles flank a gable or spire, and the like. Pinnacles may be considered primarily as added weight, where it is necessary to resist the thrust of an arch, etc. [ 1913 Webster ]

Some renowned metropolis
With glistering spires and pinnacles around. Milton. [ 1913 Webster ]

2. Anything resembling a pinnacle; a lofty peak; a pointed summit. [ 1913 Webster ]

Three silent pinnacles of aged snow. Tennyson. [ 1913 Webster ]

The slippery tops of human state,
The gilded pinnacles of fate. Cowley. [ 1913 Webster ]