Every hole has a par rating - usually 3, 4 or 5. One under means one less than this. So on a par 4 hole a score of 3 is one under par. This is called a birdie.
A score of one under par
A score for one hole that is one under par is an, "Eagle".
A birdie is one stroke under par on a given hole.
It is called a double eagle or a hole in one.
An eagle in golf is when you score two under par on the hole. Example: On a par 4 you score a 2 or on a par 5 you score a 3
You score a 3 or (1 under par)
A hole in one is very easy to score in a game of golf. This rare feat would earn you one point. If the hole is a par 4, then you would be three under par, or -3.
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.
Yes the PGA record for lowest score in one round is 13 under or a score of 59.
It is a golf term. It means to score three under par on a hole. If your par is four, you would have to get a hole in one to score a double eagle. If your par is five, you would score 2. This term is an outdated one, and is rarely used because it is rarely applicable.
My score on the front.
You would get a score of one. This would make you 2 under par for that particular hole. Your current score would depend how many strokes it took to complete whole one and two to give your current score at the end of that hole.