So what exactly is "μεσημεριανό"? When I hover over the word it shows "lunch," "brunch," and "dinner"- those are all quite different meals for me...
Μεσημεριανό is the mid-day meal (actually means "of the mid-day") , so only lunch is correct.
troll1995 is right - in Greek μεσημεριανό is only used for the midday meal (from το μεσημέρι - midday/noon). The confusion seems to stem from the fact that in some parts of the English-speaking world 'dinner' is actually used for the midday meal. See: https://en.wikipedia.org/wiki/Dinner