Eagle
A score of two strokes below par on any individual hole. Eagles are most commonly made on par-5s, where an eagle is a score of 3. An eagle on a par-4 (a score of 2) would require holing out from the fairway. An hole-in-one on a par-3 is technically also an eagle, but is never referred to as such. Why would you call it an eagle when you can call it a hole-in-one?
Sometimes confused with the term "ace". An ace and an eagle are only interchangeable on a par 3. An eagle on a par 4 or a par 5 are not considered aces. An ace is simply a hole-in-one.