To fold your arms is to cross them over the chest. Fold your arms and wait.
It is read as defensive, though it is just as often because there is nowhere else to put them. Everybody folds them the same way round every time and finds the other way impossible.
1phrasefold your armsTo cross the arms over the chest, often defensively.
“He would fold your arms the moment anybody disagreed with him.”
fold your arms is a gesture.
Practised in Body Language & Gestures