nonce word vs word

nonce word and word both are nouns.

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

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

nonce word (noun)	word (noun)
a word with a special meaning used for a special occasion	a unit of language that native speakers can identify
	a promise
	information about recent and important events
	a brief statement
	an exchange of views on some topic
	a secret word or phrase known only to a restricted group
	a verbal command for action
	a string of bits stored in computer memory

nonce word (verb)	word (verb)
	put into words or an expression