loggerheaded vs thickheaded

loggerheaded and thickheaded both are adjectives.

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

As adjectives, loggerheaded and thickheaded are synonyms defined as:

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

loggerheaded (adjective)	thickheaded (adjective)
(used informally) stupid	(used informally) stupid