Decrement
DECREMENT, noun
1. Decrease; waste; the state of becoming less gradually.
Rocks and mountains suffer a continual decrement
2. The quantity lost by gradual diminution, or waste.
3. In heraldry, the wane of the moon.
4. In crystalography, a successive diminution of the lamens of molecules, applied to the faces of the primitive form, by which the secondary forms are supposed to be produced.