Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ĕqua, ae, f. [equus], a mare, Varr. R. R. 2, 7, 4; Cic. Verr. 2, 1, 10; Verg. G. 1, 59; 3, 266; Hor. C. 2, 16, 35 et saep.
Dat. and abl. plur. equis, Varr. R. R. 2, 1, 19; Col. 6, 37, 8; Plin. 11, 41, 96, § 237; 8, 42, 64, § 156; Dig. 50, 13, 2; also, equabus, Pall. Mart. 13, 1 and 5; Serv. Verg. G. 3, 268; Cod. Just. 11, 75, 1.
ĕquĭo, īre, v. n. [equus], of mares, to be in heat, Plin. 10, 63, 83, § 181; perh. also Col. 6, 38, 1.