lexical vs word

lexical is not a noun while word is a noun.

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

lexical (noun)	word (noun)
	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

lexical (adjective)	word (adjective)
of or relating to words
of or relating to dictionaries

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