A cookie is a small, flat, sweet, baked good, usually containing flour, eggs, sugar, and either butter, oil or fat.
It may include other ingredients such as raisins, oats, chocolate chips or nuts.
In most English-speaking countries except for the US and Canada, crisp cookies are called biscuits.
Chewier biscuits are sometimes called cookies even in the UK.
Some cookies may also be named by their shape, such as date squares or bars. (source)
So can hamsters eat cookies?
Unfortunately, it is not a good idea to feed them cookies.
The sugar content in cookies is not good for them although they will devour them if they are fed to them.
If they have a nibble of them, they will be fine but the aren’t a food to be purposely fed to them.