What does the "C" stand for in "ADC"?

I've been playing the new season, playing mostly mages and I wonder what does that C stand for. Everytime I see an ADC I reaffirm my role as a mage by doing a little magic tricks which consists of making them dissappear in a single rotation. Right now my current guest is that that C means "Companion". The ADC is the companion of the team. When you have to facecheck a bush, it isn't scary if you have your companion with you, even better if you make them go first