‘牛仔裤’ literally means ‘cowboy pants’ — a direct translation of the English word ‘jeans’. The character 牛 (niú) means ‘cow’ or ‘ox’, 仔 (zǎi) is a colloquial suffix often used to denote a young male person or someone associated with a role (here, evoking ‘cowboy’), and 裤 (kù) means ‘pants’ or ‘trousers’. Though the name references cattle and American cowboys, the term is now used universally in Chinese for denim trousers of any style or gender. It’s a loanword adaptation that preserves the cultural origin while sounding natural in Mandarin.

This word is neutral in register and widely used across ages and contexts — from shopping and fashion to casual daily conversation. Unlike some clothing terms that specify gender or cut (e.g., 长裤 ‘long pants’), ‘牛仔裤’ specifically denotes denim jeans, regardless of fit, wash, or design. It’s rarely used in formal writing but extremely common in spoken Mandarin and advertising.