decidedly vs emphatically

decidedly and emphatically both are adverbs.

Word	Noun	Adjective	Verb	Adverb
decidedly	No	No	No	Yes
emphatically	No	No	No	Yes

As adverbs, decidedly and emphatically are synonyms defined as:

Other synonyms of decidedly include by all odds, definitely, in spades, unquestionably.

decidedly (adverb)	emphatically (adverb)
without question and beyond doubt	without question and beyond doubt