Unquestionably (9)

I think it could be either:

decidedly

doubtless

'unquestionably' is the definition.
(I've seen this before)

This is the entire clue.

(Other definitions for doubtless that I've seen before include "Definitely not" , "Assuredly" , "Probably, certainly" , "Unquestionably" , "Positive" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.