Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dŏmuncŭla, ae, f. dim. [domus], a small house (not ante- Aug.), Vitr. 6, 10; App. M. 4, p. 146, 31; Val. Max. 4, 4, 8; Dig. 47, 12, 3 fin. (perh. also App. M. 4, p. 154, inst. of domuscula).