IPA: /nɒnˈjuːzɪŋ/
KK: /nɑnˈjuːzɪŋ/
Not engaging in the act of using something, particularly in the context of avoiding recreational drugs.
She has chosen a nonusing lifestyle to promote her health.
Nonusing → It is formed from "non-" (meaning not) and "using" (from the verb "use", which comes from Old French *user*, meaning to employ or utilize). The word "nonusing" means not employing or utilizing something.
Think of 'not' ('non-') using something — that's why 'nonusing' means not utilizing.