Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
formōsŭlus, a, um, adj. dim. [id.], pretty (ante- and post-class.): uxor, Varr. ap. Non. 27, 5: formosulus tuus, Hier. Ep. 117, 10: formosuli nostri, id. ap. Jovin. 2, 14.