Synonyms and related words :
Boeotian, asinine, beef-brained, beef-witted, blockheaded, bovine, chuckleheaded, chumpish, cloddish, cowish, crass, dense, doltish, dull, dullard, dumb, duncical, duncish, fat, gross, ineducable, klutzy, lumpish, numskulled, oafish, opaque, sottish, stupid, thick, unteachable, wrongheaded