Hang about and While away

Hang about verb - To spend time doing nothing.

While away and hang about are semantically related In some cases you can use "While away" instead a verb "Hang about".

While away verb - Spend or pass, as with boredom or in a pleasant manner; of time.

Hang about and while away are semantically related in dawdle topic. Sometimes you can use "Hang about" instead a verb "While away".