Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
squāles, is, f. [squaleo, II.], filth, dirt: ager periret squale, Varr. ap. Non. 226, 5; 125, 33; 168, 20: squale scabieque, Pac. ib. 152, 29 (Trag. Rel. v. 314 Rib.).