Decrescent, a heraldic term by which the wane of the moon is indicated. A moon decrescent is a half-moon with her horns turned to the (heraldic) sinister—i.e. the right of the spectator.
Decrescent
Chambers's Encyclopaedia, Volume 3: Catarrh to Dion, p. 727
Source scan(s): p. 0738