You call it "the start of a golf hole."
Just the hole or the cup.
The 19th hole can be the first playoff hole after a round of golf, but it is another name for the bar after the round.
The measurement of a golf hole for a golf course is always 4 1/4 inches.
The actual hole? 4 1/4 inches or a golf hole? About 100-600 yards.
The 19th Hole
1 or 18
Hole out is simply finishing a hole of golf, obviously by putting the ball in the hole.
Albatross or double eagle.
4 and 1/4 inches.