Gibbous
/ˈɡɪb.əs/noun
Having a rounded, convex shape; especially describing the moon when more than half illuminated but not full.
Did you know?The word comes from Latin *gibbus*, meaning “hump” or “hunchback,” so a gibbous moon was originally described with the same body-image language used for a bent back.
Etymological Timeline
Latin
Latin
gibbus
“hump; hunchback; something rounded or swollen”
Late Latin
Latin
gibbosus
“humped; swollen; protuberant”
Middle French
French
gibbeux
“hump-backed; bulging”
14th Century
English
gibbous
“hump-backed; swollen; bulging”
Modern English
English
gibbous
“rounded and bulging, especially of the moon when more than half illuminated”