Unit of weight, commonly used in recipes and product labels. 1 ounce is about 28.35 grams.
このレシピではバターを4オンス使います。
This recipe uses 4 ounces of butter.
This steak is 12 ounces.
8オンスのコーヒーカップを買った。
I bought an 8-ounce coffee cup.
fluid ounce
troy ounce
Borrowed from English 'ounce'.