voluntary (n.)
- aimed
- alternative
- breakthrough
- chosen
- conscious
- descant
- elective
- exordium
- foreword
- free
- frontispiece
- independent
- innovation
- introduction
- knowing
- leap
- overture
- postulate
- preamble
- preface
- prefix
- preliminary
- prelude
- premise
- presupposition
- prolegomenon
- prolepsis
- prologue
- vamp
- verse
- volunteer
- willing
voluntary (adj.)
- advised
- aimed
- alternative
- arbitrary
- autonomous
- calculated
- chosen
- conscious
- considered
- deliberate
- designed
- discretional
- discretionary
- disjunctive
- elected
- elective
- envisioned
- free
- gratuitous
- independent
- intended
- intentional
- knowing
- meant
- meditated
- nonmandatory
- optional
- planned
- preliminary
- premeditated
- projected
- purposeful
- purposive
- self-acting
- spontaneous
- studied
- teleological
- unasked
- uncalled-for
- uncoerced
- unconstrained
- unforced
- uninfluenced
- uninvited
- unprompted
- unrequested
- unsolicited
- unsought
- verse
- volitional
- volunteer
- willful
- willing
- witting
