first base

noun

1

: the base that must be touched first by a base runner in baseball

2

: the player position for defending the area around first base

3

: the first step or stage in a course of action

plans never got to first base

first baseman

-ˈbā-smən 

noun

Examples of first base in a Sentence

a runner on first base

She hit a ground ball to first base.

He used to be a catcher, but now he plays first base.

Recent Examples on the Web

In the third, Marcelo Mayer made it to first base on a single, succeeded by a flyout and then a double play that ultimately rounded out the inning with still no points on the board for Boston and a record 16-pitches for Wheeler. —Kaitlyn McCormick, USA Today, 13 May 2026

The hitting team starts with a runner at first base, no outs and selects five batters. —Stephen J. Nesbitt, New York Times, 13 May 2026

That’s because the Yankees shortstop hurt his right middle finger while diving back to first base during the ninth inning of Sunday’s loss to the Brewers. —Gary Phillips, New York Daily News, 11 May 2026

The Rangers sent in pinch-runner Sam Haggerty at first base in the eighth inning with one out, and Taylor Clarke picked him off before delivering his next pitch. —ABC News, 11 May 2026

Word History

First Known Use

1848, in the meaning defined at sense 1

Rhymes for first base

• abase
• airspace
• apace
• backspace
• biface
• birthplace
• blackface
• boldface
• bookcase
• braincase
• briefcase
• carcase

Kids Definition

first base

noun

: the base that must be touched first by a base runner in baseball

also : the position of the player defending the area around first base