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

Left fielder Amy Cornelius made a running grab just before the fence with a runner on first base to close the second. —Dan Albano, Oc Register, 24 Apr. 2026

With Jung Hoo Lee at first base, Heliot Ramos smashed a single to center field off Dodgers right-hander Yoshinobu Yamamoto. —Justice Delos Santos, Mercury News, 24 Apr. 2026

The first-base umpire ruled the Giants had completed the double play anyway, since Adames’ throw beat Kim to first base. —Bill Shaikin, Los Angeles Times, 23 Apr. 2026

Fermin will get the start behind the plate on Thursday, while Ty France will start at first base and Miguel Anduar will start at DH. —Jeff Sanders, San Diego Union-Tribune, 23 Apr. 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