Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† āthlon, i, n. (āthla, ae, f., Petr. 57 fin., like schema, diadema, dogma; cf. Schneid. Gr. p. 274), = ἆθλον, a struggle, a work, labor, pains, Manil. 3, 162; 3, 172; 3, 193 al.; Hyg. Fab. 30.