unquestionably
adv.without any doubt at all. You use this to show that something is definitely true and nobody can argue with it.
adv.used to emphasize that a statement is completely true or that a quality is undeniable. Often functions as a sentence-modifying disjunct to express the speaker's certainty.
“She is unquestionably the best player on the team.”
“The new safety regulations are unquestionably a step in the right direction for the industry.”
“While some critics found the plot predictable, the lead actor's performance was unquestionably the highlight of the production, earning him a standing ovation.”
Typically placed before the adjective it modifies or at the beginning of a clause to emphasize the speaker's stance.
“And while he is unquestionably a “builder”, so much of that work was simultaneous with his career as a player.”
“It leaves Root as unquestionably the man in charge.”
From unquestionable + -ly or un- + question + -ably.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.