Of one’s own free will; freely and spontaneously.(adverb)
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Use "willingly" in a sentence
"His gentle doe went willingly to the covert of the wolf -- _willingly_, I repeat."
"Amit, I’m sure has had a different set of experiences with the term, and almost assuredly did not pick the term willingly to apply to himself as I did."
"You are the reason why the democratic party will be divided, the one that you follow so willingly is the reason that this party will be divided, how could you possibly know the man that you call yourselves supporting, when he is supposed to be the candidate of unity, but his followers are so nasty and divisive."