exceedingly vs deathly

exceedingly is not an adjective while deathly is an adjective.

Word	Noun	Adjective	Verb	Adverb
exceedingly	No	No	No	Yes
deathly	No	Yes	No	Yes

As adverbs, exceedingly and deathly are synonyms defined as:

Other synonyms of exceedingly include extremely, super.

exceedingly (adjective)	deathly (adjective)
	having the physical appearance of death
	causing or capable of causing death

exceedingly (adverb)	deathly (adverb)
to an extreme degree	to a degree resembling death
	to an extreme degree