the base that a runner must reach safely to score a hit, and the first of the three bases the runner must reach safely on the way to home plate in order to score a run
b.
the fielding position nearest this base
2. get to first base
first base in American English
US
Baseball
1.
the base to the left of the pitcher, the first of the four bases that a base runner attempts to reach safely
2.
the defensive position played by the first baseman