The word **留神** (liúshén) is a compound verb formed through a logical verb-object construction, where **留** means "to retain" or "to keep," and **神** refers to one's "spirit," "mind," or "attention." Literally, it means "to keep one's spirit/mind (on something)," creating the figurative meaning of "to be careful," "to pay attention," or "to take heed." It functions as a cohesive unit advising someone to maintain mental focus and alertness to avoid danger or error, effectively serving as a common warning or reminder.