hapax legomenon vs nonce word

hapax legomenon and nonce word both are nouns.

Word	Noun	Adjective	Verb	Adverb
hapax legomenon	Yes	No	No	No
nonce word	Yes	No	No	No

As nouns, hapax legomenon and nonce word are synonyms defined as:

hapax legomenon and nonce word: a word with a special meaning used for a special occasion

hapax legomenon (noun)	nonce word (noun)
a word with a special meaning used for a special occasion	a word with a special meaning used for a special occasion