Peen

Definition:

(n.) A round-edged, or hemispherical, end to the head of a hammer or sledge, used to stretch or bend metal by indentation.
(n.) The sharp-edged end of the head of a mason's hammer.
(v. t.) To draw, bend, or straighten, as metal, by blows with the peen of a hammer or sledge.

Compare peen with other words:

hammer vs. peen

peen vs. strike

hammerhead vs. peen