透支 literally means 'to penetrate and support', but in modern Chinese it functions as a verb meaning to withdraw more money than is available in an account (i.e., to overdraw), or more broadly, to use up resources—physical, mental, or temporal—beyond sustainable limits. The character 透 conveys the idea of going through or exceeding a boundary, while 支 means 'to expend' or 'to draw on'. Together, they vividly express the act of drawing beyond what is present or permitted.

This word is commonly used in both financial contexts (e.g., bank accounts, credit cards) and figurative ones—especially regarding health and energy. For example, people say 透支健康 ('overdraw one’s health') to warn against chronic overwork or poor lifestyle habits that deplete physical reserves. It carries a slightly negative, cautionary tone, implying risk or future consequence.