candid vs candidness

candid is not a noun while candidness is a noun.

Word	Noun	Adjective	Verb	Adverb
candid	No	Yes	No	No
candidness	Yes	No	No	No

candid (noun)	candidness (noun)
	the quality of being honest and straightforward in attitude and speech

candid (adjective)	candidness (adjective)
characterized by directness in manner or speech; without subtlety or evasion
openly straightforward and direct without reserve or secretiveness
informal or natural; especially caught off guard or unprepared