damned vs goddamn

damned is a noun but goddamn is not a noun.

Word	Noun	Adjective	Verb	Adverb
damned	Yes	Yes	No	Yes
goddamn	No	Yes	No	Yes

As adjectives, damned and goddamn are synonyms defined as:

Other synonyms of damned include blame, blamed, blasted, blessed, damn, darned, deuced, goddam, goddamned, infernal.

damned (noun)	goddamn (noun)
people who are condemned to eternal punishment

damned (adjective)	goddamn (adjective)
expletives used informally as intensifiers	used as expletives
in danger of the eternal punishment of Hell	expletives used informally as intensifiers

damned (adverb)	goddamn (adverb)
in a damnable manner	expressing anger, despair, frustration, approval, or surprise