过气的英文：
obsolescent
become obsolete
dying out
go out of use
outdated
go out of style
on the wane
ex-

an ex-soldier
过气军人

“A diamond is forever”. Always in fashion, never go out of style, year in and year out.
钻石是永恒的，永远时髦，永不过气，年年如此。

A breathless flight
令人喘不过气的飞行

At first, I used to run out of breath quickly, but now I can just keep on swimming.
起初我会很快喘不过气，但现在就可以一直游下去。

To become blunt.
变钝，变迟钝

To become inflated.
膨胀变得充了气的。

To become firm or gelatinous; congeal.
凝固凝结或变硬；冻结

Antiquated;ancient;long obsolete.
过时的；古老的；久已作废的

This phrase tends to become obsolete.
这个短语已渐渐成为废词。