▪ working, done, or maintained without payment: "a voluntary helper"Similarunpaidunsalariedwithout paywithout paymentfree of chargewithout chargefor nothingfor freehonoraryvolunteerunrewardedpro bono (publico)Oppositepaid
▪ supported by contributions rather than taxes or fees: "voluntary hospitals"
▪ under the conscious control of the brain.
▪ (of a conveyance or disposition) made without return in money or other consideration.
noun
1. an organ solo played before, during, or after a church service.
▪ a piece of music performed extempore, especially as a prelude to other music, or composed in a free style.
Word Originlate Middle English: from Old French volontaire or Latin voluntarius, from voluntas ‘will’.