Emily Dickinson Lexicon

GIB'BOUS, a. [L. gibbus; Fr. gibbeux; It. gibboso; Sp. giboso; Gr. κυφος, from κυπτω, to bend. Class Gb, No. 1, 2, 3, 4, 5.]

1. Swelling; protuberant; convex. The moon is gibbous between the quarters and the full moon, the enlightened part being then convex. The bones will rise, and make a gibbous member. Wiseman.
2. Hunched; hump-backed; crook-backed. Brown.