Synonyms and related words :
Vorspiel, advised, aimed, aimed at, alternative, arbitrary, autonomous, avant-propos, breakthrough, calculated, chosen, conative, concert overture, conscious, considered, contemplated, curtain raiser, deliberate, deliberated, descant, designed, discretional, discretionary, disjunctive, dramatic overture, elected, elective, envisaged, envisioned, exordium, foreword, free, free will, front matter, frontispiece, gratuitous, independent, innovation, intended, intentional, introduction, knowing, leap, meant, meditated, nonmandatory, of design, offered, operatic overture, optional, overture, planned, postulate, preamble, preface, prefix, prefixture, preliminary, prelude, premeditated, premise, presupposition, proem, proffered, projected, prolegomena, prolegomenon, prolepsis, prologue, proposed, protasis, purposed, purposeful, purposive, self-acting, self-active, self-determined, self-determining, spontaneous, studied, teleological, unasked, unbesought, unbidden, uncalled-for, uncoerced, uncompelled, unconstrained, unforced, uninfluenced, uninvited, unpressured, unprompted, unrequested, unrequired, unsolicited, unsought, vamp, verse, volitional, volunteer, willful, willing, witting