The word 加班 is formed by directly combining two meaningful characters: 加 (jiā), which means "to add" or "to increase", and 班 (bān), which means "shift" or "scheduled work period". When placed together, they create a transparent, compound concept where the first character modifies the second, literally conveying the idea of "adding a shift", that is, working beyond one's regular scheduled hours. This formation follows a common pattern in Chinese where two independent, concrete concepts are joined to produce a new, readily understandable idea.