"faint breath" is a correct and usable phrase in written English.
You can use it to describe a weak, shallow breath. For example, "He could barely detect her faint breath as she seemed to drift away in her sleep."
Our first, 500-mile drive south through the rolling desert took us to the oasis city of Yazd, with its unique skyline of tall wind towers, designed to catch any faint breaths of breeze and funnel them down into secret retreats at the heart of the huddle of mud-brick houses.
I saw her faint breaths become shorter and shorter.
The result was good news for the north-east generally as Newcastle's flickering hopes of escaping the drop were also given the faintest breath of oxygen.
She sunk into the shards as smoothly as if they were satin, as if they were snow, and the limestone gleamed around her, an ice field, each tile with its swollen pillowed edge, each with a shadow pattern faint as breath.
Then, as people stepped closer, there was the faintest of breath pushing against his chest.
A temporary, under-ventilated fumoir in a still-to-be-designated space is not for the faint-of-breath.
As he poured the wine into my glass, I heard the faint whistling of breath in his nostrils and caught a whiff of his aftershave.
THEIR words struggled for posterity above the cacophony of Foley Square, the swooshes of cars, the gargles of a fountain, the faint but constant breaths of a city alive.
