Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
morsĭuncŭla, ae, f. dim. [2. morsus], a little bite; a biting with the lips, a kissing (ante- and post-class.): formicarum, App. M. 8, p. 211, 35: teneris labellis molles morsiunculae, kisses, Plaut. Ps. 1, 1, 65.