What's the noun for pound? Here's the word you're looking for.
pound
A unit of mass equal to 16 avoirdupois ounces (= 453.592 37 g). Today this value is the most common meaning of "pound" as a unit of weight.
A unit of mass equal to 12 troy ounces (≈ 373.242 g). Today, this is a common unit of weight when measuring precious metals, and is little used elsewhere.