GIB'BOUS, adjective [Latin gibbus; Gr. to bend.] 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. 2. Hunched; hump-backed; crook-backed.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI