资料来源 : pyDict

自动地,以自由意志

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Voluntarily \Vol"un*ta*ri*ly\, adv.
   In a voluntary manner; of one's own will; spontaneously.

资料来源 : WordNet®

voluntarily
     adv : out of your own free will; "he voluntarily submitted to the
           fingerprinting" [ant: {involuntarily}]