direct current vs DC

direct current and DC both are nouns.

Word	Noun	Adjective	Verb	Adverb
direct current	Yes	No	No	No
DC	Yes	No	No	No

As nouns, direct current and DC are synonyms defined as:

direct current and DC: an electric current that flows in one direction steadily

Other synonyms of direct current include direct electric current.

direct current (noun)	DC (noun)
an electric current that flows in one direction steadily	the district occupied entirely by the city of Washington; chosen by George Washington as the site of the capital of the United States and created out of land ceded by Maryland and Virginia
	an electric current that flows in one direction steadily