peace sign vs symbol

peace sign and symbol both are nouns.

Word	Noun	Adjective	Verb	Adverb
peace sign	Yes	No	No	No
symbol	Yes	No	No	No

As nouns, symbol is a hypernym of peace sign; that is, symbol is a word with a broader meaning than peace sign:

peace sign: a symbol that represents peace, in the form of three lines within a circle.
symbol: an arbitrary sign (written or printed) that has acquired a conventional significance

peace sign (noun)	symbol (noun)
a symbol that represents peace, in the form of three lines within a circle.	something visible that by association or convention represents something else that is invisible
	an arbitrary sign (written or printed) that has acquired a conventional significance