The Collaborative International Dictionary of English v.0.48:
free-will \free-will\, freewill \free"will`\, a. Of or pertaining to free will; voluntary; spontaneous; as, a freewill offering. [1913 Webster] Freewill Baptists. See under Baptist. [1913 Webster]WordNet (r) 3.0 (2006):
freewill adj 1: done of your own accord; "a freewill offering"