Voluntary rhymes with:
singletary, singleterry, albury, alsbury, asberry, ashbury, atteberry, attebury, atterberry, brandeberry, carbary, contractionary, contrary, deberry, demary, dusenberry, dusenbury, eikenberry, essary, etcheverry, evidentiary, fortenberry, hansbury, henneberry, incendiary, intermediary, lounsberry, maberry, mccary, mcquary, norbury, precautionary, quesenberry, quesinberry, quisenberry, rasbury, retrocessionary, rittenberry, roddenberry, sainsbury, salsberry, sansbury, saulsbury, savary, singletary, singleterry, stansbury, stooksbury, thornsberry, thornsbury, trenary