zdradziecki po angielsku:

His treacherous behaviour made them all feel anxious.

You can be every kind of treacherous thing at once!

It is just going to be a more treacherous road.

The President spoke of the treacherous intentions of the enemy.

treacherous road, sea, waters

Ice had made the roads treacherous.

a treacherous Gestapo agent / sexually transmitted diseases can be insidious and sometimes without symptoms

2. If the ground or sea is treacherous, it is extremely dangerous, especially because of bad weather conditions: Snow and ice have left many roads treacherous, and drivers are warned to use caution.

A man drowned while trying to rescue a friend struggling in the river's treacherous waters.

Yet, at the same time, the economic upturn in Europe is threatened by a particularly treacherousversion of globalisation, in the shape of financial markets without frontiers.