spīna, ae, f. [root spī, whence also spicna, spīca, spinus], a thorn.
I Lit.: cum lubrica serpens Exuit in spinis vestem, Lucr. 4, 61; cf. Prop. 4 (5), 5, 1; Verg. E. 5, 39; Col. 3, 11, 5; Plin. 21, 15, 54, § 91 al.: consertum tegumen spinis, Verg. A. 3, 594; cf. Ov. M. 14, 166; id. P. 2, 2, 36; Tac. G. 17. —Of particular kinds of thorny plants or shrubs: solstitialis, Col. 2, 18, 1: alba, whitethorn , hawthorn , id. 7, 7, 2; 7, 9, 6; 3, 11, 5; Plin. 21, 11, 39, § 68; 24, 12, 66, § 108: Aegyptia, the Egyptian blackthorn or sloe , id. 13, 11, 20, § 66; 24, 12, 65, § 107: Arabica, Arabian acacia , id. 24, 12, 65, § 107.—
B Transf., of things of a like shape.
1 A prickle or spine of certain animals (as the hedgehog, sea-urchin, etc.): animantium aliae coriis tectae sunt, aliae villis vestitae, aliae spinis hirsutae, Cic. N. D. 2, 47, 121: hystrices spinā contectae (with aculei), Plin. 8, 35, 53, § 125; 9, 59, 85, § 182: spinā nocuus, Ov. Hal. 130.—
2 A fish-bone : humus spinis cooperta piscium, Quint. 8, 3, 66; Ov. M. 8, 244.—
3 The backbone , spine : caput spina excipit: ea constat ex vertebris quattuor et viginti, etc., Cels. 8, 1; 8, 9, 2; 8, 14; Plin. 11, 37, 68, § 179; Varr. R. R. 2, 7, 5; Col. 6, 29, 2; Verg. G. 3, 87; Ov. M. 8, 806: dorsi spina, Aug. Civ. Dei, 19, 4, n. 2: spina quae est in dorso, Gell. 3, 10, 7.— Hence, poet., the back , Ov. M. 6, 380; 3, 66; 3, 672.—
4 Spina, a low wall dividing the circus lengthwise , around which was the race-course; the barrier , Cassiod. Var. 3, 51; Schol. Juv. 6, 588.—
5 A toothpick : argentea, Petr. 32 fin. —
II Trop., in plur.
1 Thorns , i. e. difficulties , subtleties , perplexities in speaking and debating (class.): disserendi spinae, Cic. Fin. 4, 28, 79; cf.: partiendi et definiendi, subtleties , intricacies , id. Tusc. 4, 5, 9; cf.: hominum more non spinas vellentium, ut Stoici, id. Fin. 4, 3, 6.—
2 Cares : certemus, spinas animone ego fortius an tu Evellas agro, Hor. Ep. 1, 14, 4.—
3 Errors : quid te exemta juvat spinis de pluribus una, Hor. Ep. 2, 2, 212.