An architrave, also called an epistyle is the beam that rests on the capitals of the columns and is most associated with classical architecture.
The term can also be applied to all sides, including the vertical members, of a frame with mouldings around a door or window. The word architrave is also used to refer more generally to a style of mouldings (or other elements) framing the top of a door, window or other rectangular opening.
The word is derived from the Greek and Latin words arche and trabs combined together to mean “main beam”.
In the construction industry today however, the term architrave is frequently used to refer to any horizontal or vertical moulding that forms the surround area to a door, window or other opening, the purpose of which is to conceal the joints between the wall or ceiling and the timber casings that form the opening.