user

One that uses.

One who uses a computer, computer program, or online service.

One who uses addictive drugs.

One who or that which uses.

In law, the using or exercise, as of a right; continued use or enjoyment; the acting in a manner which implies a claim of right so to do. See non-user.

The presumptive right arising from continued user.

One who uses.

Enjoyment of property; use.

One who uses or makes use of something, a consumer.

A person who uses drugs, especially illegal drugs.