Acicula \A*cic"u*la\, n.; pl. {Acicul[ae]}. [L., a small needle, dimin. of acus needle.] (Nat. Hist.) One of the needlelike or bristlelike spines or prickles of some animals and plants; also, a needlelike crystal.
acicula n : a needle-like part or structure of a plant or animal or crystal; as a spine or bristle or crystal [also: {aciculae} (pl)] aciculae See {acicula} acicula See {aciculum} [also: {aciculae} (pl)]