'Voluntarily' definitions:

Definition of 'voluntarily'

From: WordNet
adverb
Out of your own free will; "he voluntarily submitted to the fingerprinting" [ant: involuntarily]

Definition of 'Voluntarily'

From: GCIDE
  • Voluntarily \Vol"un*ta*ri*ly\, adv. In a voluntary manner; of one's own will; spontaneously. [1913 Webster]

Synonyms of 'voluntarily'

From: Moby Thesaurus