lintel

A horizontal structural beam spanning an opening, such as between the uprights of a door or a window, and which supports the wall above.

Athelny had told him that he lived in a house built by Inigo Jones; he had raved, as he raved over everything, over the balustrade of old oak; and when he came down to open the door for Philip he made him at once admire the elegant carving of the lintel.

Then we came to a tavern with vine-leaves over the lintel,

The computing environment of the Linux operating system running on an Intel CPU; mostly in a server.