Messenger bag

Bag with a long strap worn across the body

A messenger bag is a type of sack, usually made of cloth. It is worn over one shoulder with a strap that goes across the chest resting the bag on the lower back. While messenger bags are sometimes used by couriers, they are now also an urban fashion icon. Some types of messenger bags are called carryalls. A smaller version is often called a sling bag.

This keyword could refer to multiple things. Here are some suggestions: