Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
hinnŭlus, i, m. dim. [hinnus], a young mule: tu tuum sodalem Hinnulo videas strigosiorem, Maecen. ap. Suet. Vit. Hor. (al. hinno me v. str-); cf. Plin. 8, 44, 69, § 172 Sill. N. cr.; and: hinnulus ὁ ἐξ ἵππου καὶ ὄνου, Gloss. Philox.; Vulg. Prov. 5, 19; Cantic. 2, 17; Isid. 12, 1, 22.