The word "involuntary" means happening without intention or control. Some antonyms for "involuntary" are voluntary, deliberate, intentional, and willful. Voluntary refers to something that is done by choice or willingness, while deliberate denotes a purposeful and cautious decision. Intentional and willful both imply action taken with conscious intent, but willful typically suggests stubbornness or defiance. Other antonyms for involuntary could include conscious, purposeful, willful, premeditated, and calculated. The antonyms of "involuntary" all portray actions or decisions that are made with an active choice, unlike the passive nature of something that is involuntary.