I. Lit., a spur as worn on the heel: “calcaria dicta, quia in calce hominis ligantur, ad stimulandos equos,” Isid. Orig. 20, 16, 6 (class. in prose and poetry; “esp. freq. trop.): calcari quadrupedem agitare,” Plaut. As. 3, 3, 118: incendere equum calcaribus, to spur one's horse, Hirt. B. G. 8, 48; so, “concitare,” Liv. 2, 6, 8; Curt. 7, 4, 18: “stimulare,” Val. Max. 3, 2, 9: “subdere equo calcaria,” Liv. 2, 20, 2; Curt. 3, 13, 8; 7, 2, 4: “calcaribus subditis,” Liv. 4, 19, 4; 4, 33, 7; Curt. 4, 16, 6: “equi fodere calcaribus armos,” Verg. A. 6, 881: “calcaribus auferre equum,” Sil. 10, 280.—
B. Trop., spur, stimulus, incitement: calcaribus ictus amoris, *Lucr. 5, 1074: “dicebat Isocrates se calcaribus in Ephoro, contra autem in Theopompo frenis uti solere,” Cic. de Or. 3, 9, 36: “alter frenis eget, alter calcaribus,” id. Att. 6, 1, 12; cf. id. Brut. 56, 204; Quint. 2, 8, 11; 10, 1, 74: anticipate atque addite calcar, Varr. ap. Non. p. 70, 13; * Hor. Ep. 2, 1, 217: “immensum gloria calcar habet,” Ov. P 4, 2, 36.—So also of the driving winds: ventus calcar admovere, Varr. ap. Non. p. 451, 29.—Prov.: “addere calcaria sponte currenti,” to spur a willing horse, Plin. Ep. 1, 8, 1.—
II. Transf., the spur on the leg of the cock, Col. 8, 2, 8.