blockheaded vs thickheaded

blockheaded and thickheaded both are adjectives.

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

As adjectives, blockheaded and thickheaded are synonyms defined as:

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

blockheaded (adjective)	thickheaded (adjective)
(used informally) stupid	(used informally) stupid