The word **退回** is a compound verb formed by combining two synonymous or semantically related characters: **退** (tuì), which means "to retreat," "to withdraw," or "to move back," and **回** (huí), which means "to return," "to go back," or "to circle back." Together, they create a more precise and reinforced meaning of "to send back," "to return (an item)," or "to retreat to a previous position." This type of word formation, where two characters with similar meanings are joined to clarify and specify a related action, is common in Chinese and results in a term whose meaning is logically derived from the sum of its parts, emphasizing the action of moving something or oneself backward to a point of origin.