Grapefruit is a weird thing to call a fruit that's entirely unrelated to grapes. Also grapes are already a fruit? Why is it called grapefruit.
Apparently it's called that because they grow in clusters like grapes, according to wikipedia. That's a very tenuous connection to base a name on. The clusters don't even look much like grape clusters. Should we start calling brussels sprouts grapevegetables?
@catterfly I've seen brussels sprouts on the plant before, yeah. It's just the only thing I can think of that's vaguely grape-like.