In North America (and perhaps other English speaking areas, but I'm not qualified), the article joe is used as a slang term for coffee. Usually in this usage it implies basic, black, salt of the earth coffee with none of your sissy "gourmet" flavours and "two-creams-and-three-sugars" Starbucks fluff.
The origin is probably hotly (pun intended) disputed, but from my research points to a variety of sources:
- ...a simple corruption of "java".
- ...from phrase like "average joe", meaning common and unremarkable, as coffee is one of the most consumed beverages in the world.
- ...rhyming slang from "go" or "a cup of go-juice", as coffee is also used by a huge number of people to get themselves going in the morning.