jamb 1
/jam/ , n.
1. Archit. , Building Trades.
a. either of the vertical sides of a doorway, arch, window, or other opening.
b. either of two stones, timbers, etc., forming the sidepieces for the frame of an opening.
2. Armor. greave.
Also, jambe .
[ 1350-1400; ME jambe gamba, var. of camba pastern, leg kampé bend of a limb ]
jamb 2
/jam/ , v.t., v.i. Obs.
jam 1 .