Definition of gibbous in English:



  • 1(of the moon) having the illuminated part greater than a semicircle and less than a circle.

    • ‘The moon is gibbous and yellow down at the end of the main street.’
    • ‘My hand was clasped around hers, and the light of the gibbous moon set a silver path out before us.’
    • ‘On the 16th Jupiter appears to the upper left of the waxing gibbous Moon.’
    • ‘The waxing gibbous moon was still behind the scudding clouds, but it was far from pitch dark.’
    • ‘The year is on the wane, has passed its gibbous phase and is now into that delicate fingernail-clipping shape that children draw in pictures to denote the moon.’
    1. 1.1 Convex or protuberant.
      ‘his gibbous eyes’
      • ‘The male hooded merganser, with his distinct gibbous moon crest, demands immediate attention.’


Late Middle English: from late Latin gibbosus, from Latin gibbus ‘hump’.