Well it is a 2 and it would be called a birdie.
A hole in one or an ace.
A birdie.
One under par on a hole is called a "birdie".
It is called a birdie
A birdie is a golf score. Each hole has a par score. If you do it in one less it is called a birdie.
In golf a birdie is one under par on a given hole. So a 2 on a par 3, 3 on a par 4 and 4 on a par 5.
A "birdie" is not a specific score, it's one under whatever par for the hole is. If it's a par 3 hole, then a birdie is 2; if it's a par 5 hole, a birdie is 4.
Either a par 3 and birdie 3 or an eagle 3 depends what par the hole is.
One under par
A score of one under par
A birdie is a hole played one stroke under par.
A birdie is one stroke under par on a given hole.