钻牛角尖

1. • lit. to penetrate into a bull's horn (idiom) fig. to waste time on an insoluble or insignificant problem
2. • to bash one's head against a brick wall
3. • a wild goose chase
4. • a blind alley
5. • to split hairs

Character by character

• 钻(zuān)drill
• 牛(niú)surname Niu
• 角(jiǎo)angle
• 尖(jiān)pointed