thickheaded vs duncical

thickheaded and duncical both are adjectives.

Word	Noun	Adjective	Verb	Adverb
thickheaded	No	Yes	No	No
duncical	No	Yes	No	No

As adjectives, thickheaded and duncical are synonyms defined as:

Other synonyms of thickheaded include blockheaded, boneheaded, duncish, fatheaded, loggerheaded, thick-skulled, thick, wooden-headed.

thickheaded (adjective)	duncical (adjective)
(used informally) stupid	(used informally) stupid