Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cantrix, īcis, f. [cantor], a female singer, a songstress, Plaut. Trin. 2, 1, 23; Tert. adv. Marc. 3, 5.
Adj.: aves cantrices, singing, Varr. R. R. 3, 5, 14.