The Collaborative International Dictionary
Batter rule
Batter \Bat"ter\, n. A backward slope in the face of a wall or of a bank; receding slope.
Batter rule, an instrument consisting of a rule or frame, and a plumb line, by which the batter or slope of a wall is regulated in building.
Wiktionary
batter rule
n. An instrument consisting of a rule or frame, and a plumb line, by which the batter or slope of a wall is regulated in building.