Eilenberg & Mac Lane needed a word like 'set', 'group', 'class', etc, except of course those were all taken. They claim to have gotten the word 'category' from

Eilenberg & Mac Lane needed a word like 'set', 'group', 'class', etc, except of course those were all taken. They claim to have gotten the word 'category' from Kant, although they didn't intend an actual semantic relation.