CD vs obligation

CD and obligation both are nouns.

Word	Noun	Adjective	Verb	Adverb
CD	Yes	No	No	No
obligation	Yes	No	No	No

As nouns, obligation is a hypernym of CD; that is, obligation is a word with a broader meaning than CD:

Other hypernyms of CD include certificate of indebtedness, debt instrument.

CD (noun)	obligation (noun)
a digitally encoded recording on an optical disk that is smaller than a phonograph record; played back by a laser	the social force that binds you to the courses of action demanded by that force
a debt instrument issued by a bank; usually pays interest	a legal agreement specifying a payment or action and the penalty for failure to comply
	a written promise to repay a debt
	a personal relation in which one is indebted for a service or favor
	the state of being obligated to do or pay something