"Biē niào" literally combines 憋 (to hold back, suppress) and 尿 (urine), forming a verb meaning 'to hold one's urine'—that is, to consciously delay urination despite feeling the urge. It describes a physical act involving bladder control and often implies discomfort, urgency, or self-restraint.

This expression is commonly used in everyday spoken Chinese, especially when discussing bodily functions, health concerns, or humorous or relatable situations—like being stuck in traffic, waiting for a break at work, or traveling without restroom access. While not formal or clinical, it’s widely understood and neutral in register; however, it’s rarely used in written medical contexts, where terms like 'urinary retention' (尿潴留) would apply instead.