noun

1. the celestial body that revolves around the earth from west to east in c. 27 days with reference to the stars and once in c. 29 days with reference to the sun, and that accompanies the earth in its yearly revolution about the sun: diameter, c. 3,476 km (c. 2,160 mi); mean distance from the earth, c. 384,404 km (c. 238,857 mi); mean density, c. that of the earth; mass, c.; volume, c.: with the
2. this body as it appears during a particular lunar month or period of time, or at a particular time of the month
3. a month; esp., a lunar month
4. moonlight
5. anything shaped like the moon (i.e., an orb or crescent)
6. any natural satellite; esp., a natural satellite of a planet

Etymology: ME mone < OE mona, akin to Goth mēna < IE *mēn-, month, moon (> L mensis, Gr mēn, month, mēne, moon) < base mē-, to measure

intransitive verb

1. to behave in an idle, dreamy, or abstracted way, as when in love

2. Etymology: from an earlier slang use of the noun, meaning “buttocks”

   Slang to engage in the prank of momentarily baring one's buttocks in public

Etymology: from the notion of behaving as if moonstruck

transitive verb

1. to pass (time) in mooning
2. Slang to expose one's buttocks to (someone) as a prank