-ance \-ance\ [F. -ance, fr. L. -antia and also fr. -entia.]

A suffix signifying action; also, quality or state; as, assistance, resistance, appearance, elegance. See -ancy.

Note: All recently adopted words of this class take either -ance or -ence, according to the Latin spelling.

Source: Webster's Revised Unabridged Dictionary (1913)