goddam vs goddamned

goddam and goddamned both are adjectives.

Word	Noun	Adjective	Verb	Adverb
goddam	No	Yes	No	Yes
goddamned	No	Yes	No	Yes

As adjectives, goddam and goddamned are synonyms defined as:

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

As adverbs, goddam and goddamned are synonyms defined as:

goddam and goddamned: expressing anger, despair, frustration, approval, or surprise

Other synonyms of goddam include goddamn.

goddam (adjective)	goddamned (adjective)
expletives used informally as intensifiers	expletives used informally as intensifiers

goddam (adverb)	goddamned (adverb)
expressing anger, despair, frustration, approval, or surprise	expressing anger, despair, frustration, approval, or surprise