simplex vs simple

simplex is not a noun while simple is a noun.

Word	Noun	Adjective	Verb	Adverb
simplex	No	Yes	No	No
simple	Yes	Yes	No	No

simplex (noun)	simple (noun)
	a person lacking intelligence or common sense
	any herbaceous plant having medicinal properties

simplex (adjective)	simple (adjective)
having only one part or element	(botany) of leaf shapes; of leaves having no divisions or subdivisions
allowing communication in only one direction at a time, or in telegraphy allowing only one message over a line at a time	having few parts; not complex or complicated or involved
	easy and not involved or complicated
	exhibiting childlike simplicity and credulity
	unornamented
	lacking mental capacity and subtlety
	apart from anything else; without additions or modifications