Sit back and While away

Sit back verb - Settle into a comfortable sitting position.

While away and sit back are semantically related. In some cases you can replace term "While away" with "Sit back", this phrasal verbs are similar.

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

Sit back and while away are semantically related. Sometimes you can use "Sit back" instead a verb "While away".