Without question; beyond doubt; indubitably.(adverb)
OK, right-on(adverb)
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Use "unquestionably" in a sentence
"Yet Mr. Bush's flirtation with the term unquestionably pushed Muslim intellectuals to debate the legitimacy of its use and the cult of martyrdom that had -- and may still have -- a widespread grip on many among the faithful."
"And in a charter of Charles the Simple, _circ. _ 900, the term unquestionably occurs in this latter signification, disconnected from"
"“When people curse their parents, it unquestionably is a capital crime,” he writes."