It seems like the images I looked at were split between the American definition of the word and the British definition of the word. Muddying the waters further, "biscuit" is used for both purposes in Japan, primarily as a form of cookie but also in the form of the biscuits (with a hole in them to put honey in) seen at KFC.
Naturally, there is no Wiki definition for it.
If we prefer to use the British version, then is there a good way of distinguishing a biscuit from any other type of cookie? And what should the American-style biscuit be tagged as instead?
Updated by Serlo