1. lit. honing a bull's horn; fig. to waste time on an insoluble or insignificant problem; to bash one's head against a brick wall; a wild goose chase; a blind alley; to split hairs; same as idiom 鑽牛角尖|钻牛角尖

   trad. 鑽牛角

Also written 鑽牛角【zuān niú jiǎo】