Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. trŏpa, ae, f., = τροπή, the tropic solstice: CHIMERINA, Kal. Vet. ap. Inscr. Orell. II. p. 381.
2. trŏpa, adv., turning; Gr. τρόπα (v. Lidd. and Scott, s. v.): et ludit tropa nequiore talo, i. e. at a game played by throwing dice, etc., Mart. 4, 14, 9.