unquestionably

I

(Roget's IV) modif.

Syn. certainly, without a doubt, surely, indubitably, indisputably, definitely, reliably, absolutely, positively, incontrovertibly, indefensibly, indeed, assuredly, of course, undoubtedly, certes, undeniably, unequivocally, past a doubt, beyond doubt, beyond a shadow of a doubt, past dispute.

II

(Roget's Thesaurus II) adverb It is so; as you say or ask: absolutely, agreed, all right, assuredly, aye, gladly, indubitably, roger, undoubtedly, willingly, yea, yes. Informal: OK, uh-huh, yeah, yep. Slang: right on. See AFFIRM.