Why UE4's hair rendering system called groom?

Hey, not a native-speaker here, just wandering why UE4’s hair rendering system is called groom.
I googled groom, and Cambridge Dictionary1 shows groom means : a man who is about to get married or has just got married, or someone who takes care of the horse (also quite wired, to get married v.s. take care of the horse??).

Anyway, seems groom is not very related to hair. So why the hair rendering system is called groom in UE?