Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
vannus, i (abl. heterocl. vannu, Non. 19, 21), f., a fan, van for winnowing grain, Col. 2, 20, 4; App. M. 11, p. 260, 9; 11, p. 269, 2: mystica Iacchi, borne about in the Bacchic festival, Verg. G. 1, 166.