Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† mŏnas, ădis, f., = μονάς, unity; a unit, monad (post-class.), Macr. Somn. Scip. 1, 6, 7 sqq.; Tert. adv. Val. 37; id. Praescr. 49 fin. et saep.