wager vs parlay

wager and parlay both are nouns.

Word	Noun	Adjective	Verb	Adverb
wager	Yes	No	Yes	No
parlay	Yes	No	Yes	No

As nouns, parlay is a hyponym of wager; that is, parlay is a word with a more specific, narrower meaning than wager:

wager: the act of gambling
parlay: a series of wagers in which the winnings from one wager are used as a stake for the subsequent wagers

Other hyponyms of wager include daily double, exacta, perfecta, parimutuel, place bet, superfecta, handicap bet.

wager (noun)	parlay (noun)
the act of gambling	a series of wagers in which the winnings from one wager are used as a stake for the subsequent wagers
the money risked on a gamble

wager (verb)	parlay (verb)
maintain with or as if with a bet	stake winnings from one bet on a subsequent wager
stake on the outcome of an issue