Definition:Ounce/Linguistic Note

Definition
The word ounce derives from the Latin word uncia, meaning $\dfrac 1 {12}$ part.

The word avoirdupois derives from the Normam French word whose literal translation is goods (that is property, or things owned) of weight.

The avoir part also means to have in modern French, and derives from the Latin habere.

It is pronounced something like av-wah-doo-pwah, although Francophones will be aware that there are further subtleties to this.