passercŭlus, i, m. dim. [1. passer],
a little sparrow , sparrowlet , Cic. Div. 2, 30, 65.—As a term of endearment: dic me igitur tuum passerculum, Plaut. As. 3, 3, 76.
passerculus ī, m dim.passer, a little sparrow, sparrowlet . ...
An Elementary Latin Dictionary