gibbous

Also gib·bose

[gib-uhs]

adjective

1. Astronomy.,  (of a heavenly body) convex at both edges, as the moon when more than half full.

2. humpbacked.

gibbous

/ ˈɡɪbəʊs, ˈɡɪbəs /

adjective

1. (of the moon or a planet) more than half but less than fully illuminated

2. having a hunchback; hunchbacked

3. bulging

gibbous

1. More than half but less than fully illuminated. Used to describe the Moon or a planet.

2. Compare crescent

Other Word Forms

• gibbousness noun
• gibbously adverb
• gibbosely adverb
• gibboseness noun

Word History and Origins

Origin of gibbous¹

1350–1400; Middle English < Latin gibbōsus humped, equivalent to gibb ( a ) hump + -ōsus -ous

Word History and Origins

Origin of gibbous¹

C17: from Late Latin gibbōsus humpbacked, from Latin gibba hump

Example Sentences

“The waning gibbous moon will severely compromise this shower at the time of maximum activity,” notes the American Meteor Society.

From Los Angeles Times

Viewing will also be hampered by the waning gibbous moon at 93% of its full illumination and present in the sky throughout the night.

From BBC

The Moon will be in a waxing gibbous phase – going from half moon to full moon.

From BBC

Even now, however, a waning gibbous moon will still somewhat impede viewing conditions.

From Salon

The waxing gibbous moon will set around midnight, ushering in excellent viewing conditions later in the night and predawn hours.

From National Geographic