The opposite of voluntary would be involuntary (not by choice).
If it is by outside force or regulation, the opposite would be compulsory, forced, required, or obligatory.
The opposite of compulsory (compelled) would be voluntary or optional.
They had a voluntary exchange on the apartment.
a voluntary provision is an act of giving freely without demanding for pay back, that is wholeheartedly.
Nonprofit organisation
An opposite of the word "to" is from.
Voluntary
voluntary
The opposite of compulsory (compelled) would be voluntary or optional.
The terms voluntary and automatic have opposite meanings. If a muscle is voluntary that means that it is under conscious control, rather than operating automatically.
Lateral Corticospinal Tract
Conscription is the opposite of voluntary. People are forced by law to serve in the armed forces. From Wikipedia: Conscription is the compulsory enrollment of people to some sort of public service, most often military service.)
voluntary
It means that you have free will and are able to make a conscious decision to take a specific action. The opposite is involuntary, and that means you have no conscious control of the action. An example could be the act of digestion is involuntary and the act of taking a walk down the street is voluntary behavior.
Voluntary means you have voluntary control, while the involuntary you do not have voluntary control of them.
voluntary informant
do voluntary job.
voluntary