jamb

noun

1. Architecture, Building Trades.
   1. either of the vertical sides of a doorway, arch, window, or other opening.
   2. either of two stones, timbers, etc., forming the sidepieces for the frame of an opening.
2. Armor. greave.

verb (used with or without object) Obsolete.

1. jam¹.

noun

1. a vertical side member of a doorframe, window frame, or lining
2. a vertical inside face of an opening in a wall

n.

side-piece of a door, window, etc., early 14c., from Old French jambe “pier, side post of a door,” originally “a leg, shank” (12c.), from Late Latin gamba “leg, (horse’s) hock” (see gambol).