Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pălumbŭlus, i, m. dim. [palumbes], little wood-pigeon, little dove, as a term of endearment (post-class.): teneo te meum palumbulum, meum passerem, App. M. 10, p. 249, 16; id. ib. 8, p. 213, 33.