symbol vs cornucopia

symbol and cornucopia both are nouns.

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

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

symbol: something visible that by association or convention represents something else that is invisible
cornucopia: a goat's horn filled with grain and flowers and fruit symbolizing prosperity

Other hyponyms of symbol include crossbones, horn of plenty, death's head, oriflamme, white feather, allegory, emblem.

symbol (noun)	cornucopia (noun)
something visible that by association or convention represents something else that is invisible	the property of being extremely abundant
an arbitrary sign (written or printed) that has acquired a conventional significance	a goat's horn filled with grain and flowers and fruit symbolizing prosperity