|Bounce - The amount, in degrees, the leading edge of an iron is higher than the trailing edge in the playing position|
Cavity-back - An iron in which weight in the bakc of hte clubface has been redistributed tot he perimeter of the club, increasing its moment of inertia
Center of gravity - The intersection of all the balance points of the clubhead
Lie angle - Angle of the shaft or hosel of a clubhead in relation to the sole of the clubhead
Loft - Angle of the clubface in relation to a vertical plane which is the controlling factor in shot trajectory.
Moment of inertia - A measure of the clubheads resistantce to twisting
Muscle-back - An iron with an even distribution of weight across the back.
Offset - Distance from the leading edge of the hosel to the leading edge of the face, set slightly behind the hosel
Swingweight - A way of measuring how heavy a club feels to swing
Torque - Amount of twisting, as measured along a shaft's axis