backward vs timid

backward is not a noun while timid is a noun.

Word	Noun	Adjective	Verb	Adverb
backward	No	Yes	No	Yes
timid	Yes	Yes	No	No

backward (noun)	timid (noun)
	people who are fearful and cautious

backward (adjective)	timid (adjective)
directed or facing toward the back or rear	showing fear and lack of confidence
(used of temperament or behavior) marked by a retiring nature	lacking self-confidence
retarded in intellectual development	lacking conviction or boldness or courage
having made less than normal progress

backward (adverb)	timid (adverb)
in a manner or order or direction the reverse of normal
in or to or toward a past time
at or to or toward the back or rear