The word 战友 is a compound noun formed by combining two independent characters: 战 (zhàn), meaning "war" or "battle", and 友 (yǒu), meaning "friend". It follows a common grammatical structure in Chinese called a modifier-head or coordinating compound, where the first character 战 modifies and defines the specific type of 友. Literally, it means "battle friend", but semantically it fuses into the single, culturally resonant concept of "comrade-in-arms", referring specifically to the profound bond forged between individuals who serve together in military conflict.