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, definitely, emphatically, in spades, unquestionably
Decidedly ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Marathi. Decidedly ka matlab kya hota hai?