The word 后退 is formed through the logical and directional combination of its two component characters: 后 (hòu), meaning "behind" or "back", and 退 (tuì), meaning "to retreat" or "to withdraw". The formation is conceptually straightforward, where 后 establishes the spatial orientation (backward) and 退 supplies the core action of moving. When placed together, they sequentially depict the action of moving in a backward direction, creating the unified meaning "to move back" or "to retreat". It is a direct compounding of meaning, where the first element modifies the second by specifying its directional path.