caller vs bettor

caller and bettor both are nouns.

Word	Noun	Adjective	Verb	Adverb
caller	Yes	Yes	No	No
bettor	Yes	No	No	No

As nouns, bettor is a hypernym of caller; that is, bettor is a word with a broader meaning than caller:

caller: the bettor in a card game who matches the bet and calls for a show of hands
bettor: someone who bets

Other hypernyms of caller include better, punter, wagerer.

caller (noun)	bettor (noun)
a social or business visitor	someone who bets
the person initiating a telephone call
the person who convenes a meeting
someone who proclaims or summons in a loud voice
a person who announces the changes of steps during a dance
the bettor in a card game who matches the bet and calls for a show of hands
an investor who buys a call option

caller (adjective)	bettor (adjective)
providing coolness
fresh