拆信 literally means 'to tear open a letter' — 拆 (chāi) means 'to dismantle, to undo, or to open by breaking a seal', and 信 (xìn) means 'letter' or 'mail'. Together, 拆信 refers specifically to the physical act of opening an envelope containing a written message, often one received by post. It emphasizes the moment of access — breaking the seal, unfolding the flap, or extracting the contents — rather than merely reading it.

This verb is commonly used in daily life when referring to personal correspondence, formal notices, or official documents delivered by mail. While digital communication has reduced its frequency, 拆信 remains idiomatic and natural in contexts involving physical letters, such as receiving birthday cards, job application responses, or government notifications. It carries a subtle sense of anticipation or significance — the act implies something important or personal awaits inside.