gibbous

From Middle English gibbous, from Latin gibbus (“humped, hunched”), probably cognate with cubō (“bend oneself, lie down”), Italian gobba (“humpback”), Greek κύφος (kýfos, “humpback, bent”), κύβος (kývos, “cube, vertebra”), Spanish giboso (“humped”). Also ultimately compare dialectal Norwegian keiv (“slanted, wrong”), German schief (“crooked, slanting”) and Dutch scheef (“crooked, slanting”).

• IPA^(key): /ˈɡɪbəs/; (uncommon, nonstandard) IPA^(key): /ˈd͡ʒɪbəs/[1]

• Audio (Southern England)

  (file)

• Rhymes: -ɪbəs

gibbous (comparative more gibbous, superlative most gibbous)

1. Curved or bulged outward.
   • 1886 May, Thomas Hardy, “chapter 22”, in The Mayor of Casterbridge: The Life and Death of a Man of Character. […], volumes (please specify |volume=I or II), London: Smith, Elder & Co., […], →OCLC:

     In fact, what these gibbous human shapes specially represented was ready money—money insistently ready [...]

2. (astronomy, of a celestial body) Having more than half (but not the whole) of its disc illuminated.
   • 2021, Ruth Ozeki, The Book of Form and Emptiness, Canongate Books (2022), page 252:

     On December 7, 1972, the Apollo 17 astronauts took a photograph of a gibbous Earth at a distance of eighteen thousand miles from its surface.

3. Humpbacked.
   • 1697, Virgil, “The Eighth Book of the Æneis”, in John Dryden, transl., The Works of Virgil: Containing His Pastorals, Georgics, and Æneis. […], London: […] Jacob Tonson, […], →OCLC:

     A pointed flinty rock, all bare and black,
     Grew gibbous from behind the mountain's back;

• crescent

• gibbous moon
• waning gibbous