What is Non-usage?

Non-usage definition and meaning on Dictionary terms:
a customary way of doing something; a custom or practice: the usages of the last 50 years.
the customary manner in which a language or a form of a language is spoken or written: English usage; a grammar based on usage rather than on arbitrary notions of correctness.
a particular instance of this: a usage borrowed from French.
any manner of doing or handling something; treatment: rough usage.
habitual or customary use; long-continued practice: immemorial usage.
an act of using or employing; use.