boneheaded vs blockheaded

boneheaded and blockheaded both are adjectives.

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

As adjectives, boneheaded and blockheaded are synonyms defined as:

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

boneheaded (adjective)	blockheaded (adjective)
(used informally) stupid	(used informally) stupid