moon Definition

moon¹
noun

1. The Earth's natural satellite, illuminated to varying degrees by the Sun depending on its position and often visible in the sky, especially at night.

Form: Moon (often)
2. The appearance of the Moon to an observer on Earth, especially in terms of its degree of illumination, eg full moon, half moon. See also crescent, new moon.
3. A natural satellite of any planet.

Example: the moons of Jupiter
4. Something impossible to obtain.

Example: promised me the moon
5. literary, old use
A month.

Derivative: moonless
adj

Idiom: over the moon

colloq
Thrilled; delighted.

Etymology: Anglo-Saxon mona.

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moon²
verb, intr mooned, mooning

1. To wander around aimlessly; to spend time idly.

Thesaurus: brood, mope, languish, pine, daydream, fantasize.
Form: moon about (usually)
Form: moon around
2. slang
To make a show of one's bare buttocks in public.

Derivative: mooner
noun

Etymology: 1960s in sense 2, from a resemblance to the moon¹; 19c in sense 1, referring to the behaviour of someone who is moonstruck.