free·will /ˈfriˌwɪl/
  (a.)自由意志的,任意的,自願的
  free-will, free·will a. Of or pertaining to free will; voluntary; spontaneous; as, a freewill offering.
  Freewill Baptists. See under Baptist.
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  freewill
       adj : done of your own accord; "a freewill offering"