mat6 bat1 tau3 fung1密不透風密不透风

Jyutpingmat6 bat1 tau3 fung1

Yalemaht bāt tau fūng

形容詞

Definition

Airtight; wrapped up so tightly that no air can get in.

colloquialdescriptions

How it's used

While this idiom is often used literally to describe physical sealing, it is frequently applied metaphorically to describe situations where information is kept strictly confidential. It conveys a sense of extreme thoroughness, implying that not even a tiny detail could leak out. It is a common way to emphasize that something is completely impenetrable or secure.

Examples

ni1呢go3個hap6盒fung1封dou3到mat6密bat1不tau3透fung1風，dim2點joeng2樣daa2打hoi1開aa4呀？

This box is sealed airtight, how do I open it?

keoi5佢zoeng1將di1啲saam1衫baau1包dou3到mat6密bat1不tau3透fung1風，geng1驚wui2會zing2整sap1濕。

He wrapped the clothes up tight, afraid they would get wet.

Common phrases

fung1封dou3到mat6密bat1不tau3透fung1風

sealed airtight

baau1包dou3到mat6密bat1不tau3透fung1風

wrapped up tight

Common mistake

Learners often mistake this for a simple adjective like 實, but it carries a much stronger, more dramatic emphasis on the total absence of gaps. It is not used to describe a person who is simply quiet or reserved.