In Russian, being a “fan” of a team is the same word as “being sick”
The Volokh Conspiracy 2017-10-30

Russian fans at the men’s preliminary round ice hockey game between Russia and Slovakia at the Sochi 2014 Winter Olympic Games. (Photo: REUTERS/Laszlo Balogh)
The English word “fan” — in the sports context — of course comes from “fanatic.” But in Russian, the word is болельщик (bol’el’shchik); “to be a fan of” is “болеть за” (bol’et’ za). And “болеть” is the same word as “to be sick for”; “болезнь” means “illness,” and the related “боль” means “pain.”
So if you’re a fan of a sports team, in Russian, you’re being sick for the team. This might be one reason that, other than for a few short years in my childhood, I’ve never been a fan.