IPA: /nɒnˈvɒlənˌtɛri/
KK: /nɑnˈvɑlənˌtɛri/
Describing something that is done without choice or consent, often imposed by external factors.
The treatment was nonvoluntary, meaning the patients had no say in the decision.
Nonvoluntary → It is formed from "non-" (meaning not) and "voluntary" (from Latin "voluntarius", meaning willing or of one's own choice). The word "nonvoluntary" means not done by one's own choice or will.
Think of 'not' ('non-') doing something 'willingly' ('voluntary') — that's why nonvoluntary means something done without choice.