IPA: /nɒnˈvaɪələntli/
KK: /nɑnˈvaɪələntli/
In a way that does not involve violence or physical force.
The protesters marched nonviolently to express their demands for change.
Nonviolently → It is formed from "non-" (meaning not) and "violent" (from Latin "violentus", meaning violent or forceful) and the suffix "-ly" (meaning in a manner of). The word "nonviolently" means in a manner that is not violent or forceful.
Think of 'not' ('non-') and 'forceful' ('violent') to remember that 'nonviolently' means acting in a way that avoids violence.