the first nine holes of a course. 1-9. Also known as the first nine or the outward nine.
The first nine holes of an eighteen hole round.
These are holes 1 - 9. Also referred to as `going out.'
The first nine holes on an 18-hole course.
The first nine holes of an 18 hole course.
The first half of your round of golf; the second half is the back nine holes.