employment (n)
exercise (n)
usage (n)
use (n)
utilisation (n)
utilization (n)

Definition: the act of using
Example: he warned against the use of narcotic drugs. skilled in the utilization of computers.

custom (n)
usage (n)
usance (n)

Definition: accepted or habitual practice

usage (n)

Definition: the customary manner in which a language (or a form of a language) is spoken or written
Example: English usage. a usage borrowed from French.