sweepstakes vs lottery

sweepstakes and lottery both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweepstakes	Yes	No	No	No
lottery	Yes	No	No	No

As nouns, lottery is a hypernym of sweepstakes; that is, lottery is a word with a broader meaning than sweepstakes:

sweepstakes: a lottery in which the prize consists of the money paid by the participants
lottery: players buy (or are given) chances and prizes are distributed by casting lots

Other hypernyms of sweepstakes include drawing.

sweepstakes (noun)	lottery (noun)
a lottery in which the prize consists of the money paid by the participants	players buy (or are given) chances and prizes are distributed by casting lots
	something that is regarded as a chance event