For the record, that's what people here on the DIS (and maybe on other forums) call them. If you call Disney and say, "I'd like to make an ADR", chances are the Cast Member will have no idea what you're talking about - unless maybe you've said something like, "I'd like to make an ADR for Le Cellier", and you're speaking with a perceptive CM or one who happens to also be a DISer.
Walt Disney World refers to them simply as "reservations", even though they're not reservations in the standard sense, but more like 'super call-ahead seating' - only instead of calling the 99 before you leave the house, you call Disney
six months before you get on the plane