noun
fluid ounce
A unit of volume used mainly in the US and UK; the exact amount differs between the US customary and imperial systems.
このレシピでは、牛乳を8液量オンス使います。
This recipe uses 8 fluid ounces of milk.
オンス alone usually refers to the weight ounce (oz), while 液量オンス specifically means fluid ounce (fl oz).
Compound of 液量 (liquid measure) and オンス (ounce), a direct translation of the English 'fluid ounce'.