Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
gĕlum, i, n., and gĕlus, ūs, m. (nom. gelu, n., Prisc. 658 P.; but only found in Liv. ap. Non. 207, 30, a corrupt passage; and freq. in Vulg., e. g. Dan. 3, 69; Zach. 14, 6: gelum, Lucr. 6, 877; Varr. R. R. 1, 45, 2; gen. geli, Lucr. 5, 205 al.; nom. gelus, Att. ap. Prisc. 6, p. 685 P.; cf. Non. 208, 1, Fragm Trag. v. 390 Rib.; Afran. ap. Non. 207, 32, Com. Fragm. v. 106 Rib.; Cato, R. R. 40, 4 al.; acc. gelum, m., Cat. Orig. 2, Fragm. 30; abl. gelu, m., Mela, 3, 5 ext.; Flor. 4, 12, 18; Plin. Pan. 12) [root γαλ-, to be bright; whence γελάω, to laugh (cf. κυμάτων γέλασμα, Aesch. Pr. 90); γάλα, milk; γαλήνη, calm; cf.: lac, glacies; cf. Curt. Gr. Etym. p. 172], icy coldness, frost, cold (cf.: pruina, glacies, rigor).