Wiktionary
first down
n. 1 (context American football English) The first play in a series that has a maximum of four downs. 2 (context American football English) The act of getting a ''first down'' by advancing the ball more than ten yards ahead of the field position where the team took possession.
Usage examples of "first down".
Life-size statues of all the Sun Kings, from Bahlam the first down through Gordon, were set in niches along the corridor, flanked by intricately ornamented obelisks glorifying their reigns.