Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dēmĭnūtīvus, a, um, adj. [deminuo, no. II. B.], in the later gramm. lang., diminutive: vox, Tert. Apol. 32: nomen, a diminutive, Don. p. 1744 P. sq.; in this sense often subst. dēminūtīvum, i, n., Diom. p. 312 P.; Prisc. p. 609 sq. et saep: verba (sorbillo from sorbeo, garrulo from garrio), id. p. 827 P.
Adv.: dēmĭnūtīvē, as a diminutive: cymbia deminutive a cymba dicta, Macr. S. 5, 21 al.; al. diminutive.