dollar vs coin

dollar and coin both are nouns.

Word	Noun	Adjective	Verb	Adverb
dollar	Yes	No	No	No
coin	Yes	No	Yes	No

As nouns, coin is a hypernym of dollar; that is, coin is a word with a broader meaning than dollar:

dollar (noun)	coin (noun)
a symbol of commercialism or greed	a flat metal piece (usually a disc) used as money
a piece of paper money worth one dollar
a United States coin worth one dollar
the basic monetary unit in many countries; equal to 100 cents

dollar (verb)	coin (verb)
	form by stamping, punching, or printing
	make up