Though, https://www.reddit.com/r/catsinpants/ works for both forms of English.
“Biscuit” is not a category of foods in the US, while “cookie” is absolutely a category of desert with many different kinds.
If you ask for a biscuit here, you’ll get the same thing every time. If you ask for a cookie, you’ll be asked “what kind?”
Gasoline is from gas + plus the chemical suffix "ol" short for the latin "oleum", and "ine" meaning "made of".
the confusion is solely in your reading comprehension skills and not in the GP's use of the words