symbol vs numeral

symbol and numeral both are nouns.

Word	Noun	Adjective	Verb	Adverb
symbol	Yes	No	No	No
numeral	Yes	Yes	No	No

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

symbol: an arbitrary sign (written or printed) that has acquired a conventional significance
numeral: a symbol used to represent a number

symbol (noun)	numeral (noun)
something visible that by association or convention represents something else that is invisible	a symbol used to represent a number
an arbitrary sign (written or printed) that has acquired a conventional significance	a word expressing a number.

symbol (adjective)	numeral (adjective)
	of or relating to or denoting numbers