Well.... you've obviously haven't been to Kentucky!
They drink their bourbon with branch water. (a branch being a creek)
it's just a 'fancy' way of saying "bourbon with water" for those that drink it that way.
when i was still working, i used to collect 'em. must've had over a 100.
drank 'em all. (with some help of course, over a very long time....)
i like it neat in a shot glass straight up.