Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Fēbrŭa, ōrum, n., v. februum.
fēbrŭum, i, n. Orig., in the Sabine lang., a purgation, means of purification.
Hence, februa, ōrum, n., the Roman festival of purification and expiation, celebrated on the 15th of the month hence called February (v. Februarius); whence, Februālis, Febrūlis, and Februāta, surnames of Juno, who was worshipped at this festival; Februātus, the festival itself; and Februus, a surname of Lupercus, who presided over this festival: Lupercalia dicta, quod in Lupercali luperci sacra faciunt. Rex cum ferias menstruas Nonis Februariis edicit, hunc diem Februatum appellat. Februum Sabini purgamentum, et id in sacris nostris verbum; nam et Lupercalia februatio, Varr. L. L. 6, § 13 Müll.; cf. Serv. Verg. A. 8, 343: Ego arbitror Februarium a die Februato, quod tum februatur populus, id est lupercis nudis lustratur antiquum oppidum Palatinum gregibus humanis cinctum, id. ib. 6, § 34; cf. also Paul. ex Fest. p. 85, 13 sq. Müll.: Februa Romani dixere piamina patres, Ov. F. 2, 19; 4, 726; 5, 423: Juno pulchra … nam Fluoniam, Februalemque ac Februam mihi poscere non necesse est, cum nihil contagionis corporeae sexu intemerata pertulerim, Mart. Cap. 2, § 149: Februlis, Paul. ex Fest. p. 85, 16 Müll.; Arnob. 3, p. 118 (dub. al. Februtis).