Portuguese
contrail 
An artificial cloud made by the exhaust of jet aircraft or wingtip vortices that precipitate a stream of tiny ice crystals in moist, frigid upper air.
1
The sky was powder blue and cloudless -not even a contrail.
2
Threads of the yellow contrail hung in the limbs of the trees.
3
Skies as delicate as translucent china, unscarred by cloud or contrail.
4
Then he looked up and saw the contrail of an airliner, high overhead.
5
A horizontal contrail of scintillating dust stretched out through the air behind them.
1
He was still watching the vapor trail as the cab pulled away.
2
A straight, narrow line pointed dead ahead: the vapor trail from Teela's flycycle.
3
I swear she moves so fast she leaves a vapor trail most days.
4
Its vapor trail spread, cold silver on a sky of slate.
5
High above, a white vapor trail streaked a cloudless blue sky.
1
It showed footage of a missile launch in desert-like terrain, leaving a vapour trail.
2
In a time of darkness smoke stacks are soon lost, a vapour trail drifts in the dawn light.
3
As it passed over the Grand Teton National Park, one alert tourist photo-graphed the incandescent fireball and its long vapour trail.
4
But there was never any sign of their presence, save an occasional vapour trail high against the blue of the stratosphere.
5
Using her ball control, Var moved the pointer up alongside one of the satellites, pausing it on a lengthy vapour trail.
1
A condensation trail arced suddenly into the sky, launched from one of the Iscan heavies.
2
Condensation trails are a consequence of interaction between the exhaust gases from a plane's engines and the surrounding air.
3
But in fact he was curious about condensation trails, those elongated streaks of cloud that form a wake behind high flying aircraft.