animulus

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

ănĭmŭlus, i, m. dim. [animus], only in the voc. as term of endearment (cf. animus, II. B. 2. f.):

Mi animule, my heart , my darling , Plaut. Cas. 1, 46: Animule mi, id. Men. 2, 3, 11.