An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Decreasing in strength, intensity, power, etc.

Waning, from wane, from M.E. wanen (v.), O.E. wanian "to lessen;" cf. O.S. wanon, O.N. vana, O.Fris. wania, M.Du. waenen, O.H.G. wanon "to wane, to grow less."

Kâhandé "waning, decreasing;" from kâstan, kâhidan "to decrease;" Mid.Pers. kâhitan, kâstan, kâhênitan "to decrease, diminish, lessen;" Av. kasu- "small, little" (Mod.Pers. keh); Proto-Iranian *kas- "to be small, diminish, lessen."

The crescent phase of the Moon following the → last quarter which finally disappears with setting Sun.

→ waning; → crescent.

The oval shape of the moon a few days after the → full moon and before the → last quarter.

→ waning; → gibbous.

The circumstance when the phase of the Moon is decreasing from → full moon to → new moon.

→ waning; → moon.