Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cŭcŭmis, ĕris (is, sometimes in the Nat. Hist. of Pliny; e. g. acc. cucumim, Plin. 9, 2, 1, § 3; 20, 1, 2, § 3; abl. cucumi, id. 20, 9, 40, § 103 al.; together with cucumeris, id. 19, 5, 23, § 68; 19, 12, 61, § 186: cucumeres, id. 19, 5, 24, § 69 (cucumis, Sillig): cucumerum, id. 19, 5, 23, § 68 al.), m.