compact disk vs CD

compact disk and CD both are nouns.

Word	Noun	Adjective	Verb	Adverb
compact disk	Yes	No	No	No
CD	Yes	No	No	No

As nouns, compact disk and CD are synonyms defined as:

compact disk and CD: a digitally encoded recording on an optical disk that is smaller than a phonograph record; played back by a laser

Other synonyms of compact disk include compact disc.

compact disk (noun)	CD (noun)
a digitally encoded recording on an optical disk that is smaller than a phonograph record; played back by a laser	a digitally encoded recording on an optical disk that is smaller than a phonograph record; played back by a laser
	a debt instrument issued by a bank; usually pays interest