Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
histrĭōnĭa, ae, f. (sc. ars) [id.], the art of stage-playing, dramatic art: facere histrioniam, to assume the character of an actor, Plaut. Am. prol. 90; Macr. S. 2, 10, 12: exercere, Petr. Fr. 10.