There’s Jam on the Door Jamb
A jamb is a vertical post or piece that forms one side of a door, a window frame, or a fireplace. It always has one or more partners.
Jamb in Old French meant a leg, and it descended from the Latin gamba, a horse’s hock. (Thus, it is connected to the words gambol and gambit.)
A hock corresponds to the human ankle, but it bends the other way. Science fiction movies sometimes show aliens in the guise of humans, but with grotesquely-jointed legs.
[ reference The Arrival]
The word jamb has had a colorful and varied history.
• On a coat-of-arms, a jamb was a leg.
• In military history, it was armor meant to cover a good portion of a soldier’s leg.
• A jamb was the projecting wing of a building.
• It was a projecting column or pillar in a mine or a quarry.
• Also in mining, jamb signified a bed of clay or stone running across a mineral vein or seam.
• At one time, it was an angular turn or corner in a street or an alleyway.
• And in Nigeria, JAMB is an acronym for Joint Admissions and Matriculation Board.
SIDEBAR: Jamba Juice [on David Letterman]
SIDEBAR: Replacing a split door jamb
(substitute @ for AT above)