decrementum

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

dēcrēmentum, i, n. [decresco],

a diminution, decrease (post-class. for deminutio): rerum atque hominum, Gell. 3, 10, 11: lunae, Ap. Met. 11, 1, 10.