Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* per-pŭsillus, a, um, adj., very small, very little: pusillus testis processit … Non accusabis: perpusillum rogabo, in a double sense (adj. or adv.), I will ask very little, or, the very little man, Cic. de Or. 2, 60, 245.