first base

noun

1

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

a runner on first base

2

: the player position for defending the area around first base

hit a ground ball to first base

3

: the first step or stage in a course of action

Plans never got to first base.

4

slang : amorous light touching or kissing

Unless the game has changed since I was a girl, first base was kissing …

—Abigail Van Buren

—usually used in phrases like get to first base or reach first base

"It's true!" Pamela said. "If they talk about getting to first base, it means they held hands with their girl. …"

—Phyllis Reynolds Naylor

compare home base sense 3, second base sense 3, third base sense 3

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

Able to play all three outfield positions and first base, Bellinger has always been considered a strong defender. — Gary Phillips, New York Daily News, 2 Nov. 2026

Then Ben Williamson ended it with a very Brewers-like hit, a ground ball to the right side that took a huge bounce over first base to reach the outfield. — Ian Miller Outkick, FOXNews.com, 28 Oct. 2026

Chourio, who is just 22, then came up and collected his second hit of the inning, a double to plate Hamilton from first base. — Hannah Keyser, CNN Money, 26 Oct. 2026

DeLuca missed his attempt at a diving catch on Christian Yelich’s one-out drive in the first inning with Jackson Chourio on first base. — ABC News, 24 Oct. 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