ground floor
first floor

If you go here, do not stay on the ground floor.

The rest of the ground floor was given over to the service areas.

"They want to get in on the ground floor of a particular industry."

He decided to start with the ground floor and after getting no answer went on up the list.

The car was on the ground floor, the door open.

Later, the control room was moved down to the ground floor.

No one else had come all the way up from the ground floor.

Why were they both down here on the ground floor?

Some started on the ground floor and worked their way up.

Both were at ground floor, but only one had a light on inside.