To waste time or energy on insignificant or insoluble problems; to be overly stubborn or obsessive about a dead end.

(metaphor) an insignificant, trifling, or unsolvable problem that is not worth pursuing; often used in the phrase [[钻牛角尖|鑽牛角尖|zuan1 niu2 jiao3 jian1]] to mean hairsplitting or overthinking

literally to hang one's books on cow horns; refers to the story of Li Mi from the Tang Dynasty who was so diligent he hung books on his ox's horns to read while traveling

a type of long, tapered chili pepper shaped like a cow's horn, such as the cayenne pepper

common name for various types of acacia or wattle trees and shrubs

croissant; a crescent-shaped pastry

The horn of a rhinoceros, used in traditional medicine or for carving into ornaments; also called [[犀角|犀角|xi1 jiao3]]

An abnormal phenomenon or something that goes against the laws of nature, literally meaning 'a hornless bull and a horse with horns'.

To waste time on insignificant or insoluble problems; to reach a dead end by focusing on trivialities

type of bread or pastry shaped like a cow's horn; croissant