thorough vs thoroughness

thorough is not a noun while thoroughness is a noun.

Word	Noun	Adjective	Verb	Adverb
thorough	No	Yes	No	No
thoroughness	Yes	No	No	No

thorough (noun)	thoroughness (noun)
	conscientiousness in performing all aspects of a task
	property of being marked by full detail, complete in all respects.

thorough (adjective)	thoroughness (adjective)
painstakingly careful and accurate
performed comprehensively and completely; not superficial or partial
without qualification; used informally as (often pejorative) intensifiers