increment
n.
5ME < L incrementum < base of increscere, to INCREASE6
1 the fact of becoming greater or larger; increase; gain; growth
2 a) amount of increase !an annual increment of $300 in salary" b) an increase, usually small, often one of a series
3 Math. the quantity, usually small, by which a variable increases or is increased: a negative increment results in a decrease
in#cre[men4tal 73ment4‘l8
adj.

Please note that that "excrement" is not the antonym of "increment".