any powered vessel which is used for towing.

a powerful small boat designed to pull or push larger ships

a vessel that moves barges up and down the inland rivers and intra coastal waterways of the United States

A towboat is a boat designed for pushing barges. Towboats are characterized by a square bow with steel knees for pushing and powerful engines. They are most often seen on inland waterways where they can push more than 50 large barges lashed together into a tow.