gibbous

adjective

gib·​bous ˈji-bəs  ˈgi- 

1

a

: marked by convexity or swelling

b

of the moon or a planet : seen with more than half but not all of the apparent disk illuminated

2

: having a hump : humpbacked

Did you know?

The adjective gibbous has its origins in the Latin noun gibbus, meaning "hump." It was adopted into Middle English to describe rounded, convex things. While it has been used to describe the rounded body parts of humans and animals (such as the back of a camel) and to describe the shape of certain flowers (such as snapdragons), the term is most often used to describe the moon: a gibbous moon is one that is between half full and full.

Examples of gibbous in a Sentence

Recent Examples on the Web

The waxing gibbous Moon in your sign squares off against Mercury and passes through conjunction with Saturn. —Jennifer Culp, Them, 1 Nov. 2024

The ability to see the shooting stars depends on clear nighttime skies, as a bright waning gibbous moon moves between full and last quarter phases, outshining more faint meteors and reducing the number of meteors visible to sky-gazers. —Greg Wehner, Fox News, 21 Oct. 2024

As a bonus sight, a few hours after sunset a bright waning gibbous moon will rise in the east just below the Pleiades, a sparkling open cluster of stars that are always a spectacular sight to both the naked eye and binoculars. —Jamie Carter, Forbes, 19 Oct. 2024

Spectators have to contend with a nearly full bright waning gibbous moon that will outshine fainter meteors. —Katie Wiseman, The Courier-Journal, 18 Oct. 2024

Word History

Etymology

Middle English, from Late Latin gibbosus humpbacked, from Latin gibbus hump

First Known Use

14th century, in the meaning defined at sense 1a

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Kids Definition

gibbous

adjective

gib·​bous ˈjib-əs  ˈgib- 

: seen with more than half but not all of the disk lighted

gibbous moon

Medical Definition

gibbous

adjective

gib·​bous ˈjib-əs  ˈgib- 

1

: marked by swelling or convexity especially on one side : protuberant

2

: having a hump