Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ālĕo, ōnis, m. (rare, for the class. aleator), a gamester, Naev. ap. Fest. 24: impudicus et vorax et aleo, Cat. 29, 2; 6, 11; Tert. Fug. ap. Pers. 13.