deadly vs deucedly

deadly is an adjective but deucedly is not an adjective.

Word	Noun	Adjective	Verb	Adverb
deadly	No	Yes	No	Yes
deucedly	No	No	No	Yes

As adverbs, deadly and deucedly are synonyms defined as:

Other synonyms of deadly include devilishly, insanely, madly.

deadly (adjective)	deucedly (adjective)
exceedingly harmful
extremely poisonous or injurious; producing venom
involving loss of divine grace or spiritual death
(of a disease) having a rapid course and violent effect
causing or capable of causing death
of an instrument of certain death

deadly (adverb)	deucedly (adverb)
(used as intensives) excessively	(used as intensives) excessively
as if dead