Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pĭsinnus, a, um, adj., small, little; only as subst.: pĭsinni, ōrum, m., little ones, children: crudum manduces Priamum Priamique pisinnos, Labeo ap. Schol. Pers. 1, 4.