ground floor noun
plural ∼ floors [count] : the floor of a building that is at ground level —called also (US) first floor
in on the ground floor
◊If you are/get in on the ground floor of something (such as a new business or project), you become involved in it at the very beginning.
▪ He was able to get in on the ground floor of the computer industry.
▪ He was able to get in on the ground floor of the computer industry.
