Definition: A duffle coat is a warm coat that is made from a thick material called duffel. It usually has a hood and fastens with toggles (which are like large buttons made of wood or plastic).
In more advanced conversations, you might discuss the history of the duffle coat or its popularity in fashion. For example, you could say, "The duffle coat has become a classic piece in winter wardrobes, often associated with British style."
While there aren't specific idioms or phrasal verbs that include "duffle coat," you might hear phrases like "bundle up" which means to wear warm clothes, including a duffle coat, to stay warm.
A duffle coat is a cozy, stylish option for cold weather.