Meaning : Without question.
Example :
Fred Winter is unquestionably the jockey to follow.
They hired unimpeachably first-rate faculty members.
Synonyms : unimpeachably
Meaning : Without question and beyond doubt.
Example :
It was decidedly too expensive.
She told him off in spades.
By all odds they should win.
Synonyms : by all odds, decidedly, definitely, emphatically, in spades
Unquestionably meaning in Bengali (Bangla).