n. & v.
n. the wedge-shaped or thin or curved end of a hammer-head (opp. FACE n. 5a).
v.tr. 1 hammer with a peen. 2 treat (sheet metal) with a stream of metal shot in order to shape it.
[ 17th c.: also pane, app. f. F panne f. Du. pen f. L pinna point ]