knotty vs complex

knotty is not a noun while complex is a noun.

Word	Noun	Adjective	Verb	Adverb
knotty	No	Yes	No	No
complex	Yes	Yes	No	No

knotty (noun)	complex (noun)
	a whole structure (as a building) made up of interconnected or related structures
	a conceptual whole made up of complicated and related parts
	(psychoanalysis) a combination of emotions and impulses that have been rejected from awareness but still influence a person's behavior
	a compound described in terms of the central atom to which other atoms are bound or coordinated

knotty (adjective)	complex (adjective)
highly complex or intricate and occasionally devious	complicated in structure; consisting of interconnected parts
used of old persons or old trees; covered with knobs or knots	difficult to analyze or understand
making great mental demands; hard to comprehend or solve or believe
tangled in knots or snarls