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

Trailing 2-1 in the bottom of the eighth, Piazza stepped to the plate with one out and a runner on first base. — Peter Sblendorio, New York Daily News, 10 Sep. 2026

Rumfield also shouted out current Yankees coaches Dan Fiorito (first base), Ryan Hunt (director of infield, outfield, base running) and Jake Hirst (assistant hitting coach). — Brendan Kuty, New York Times, 8 Sep. 2026

Skenes also got a big play from the Pirates’ defense in the fifth inning when Zach Neto was thrown out trying to score the tying run from first base on Mike Trout’s two-out double. — Los Angeles Times, 6 Sep. 2026

Ildemaro Vargas moved from first base to shortstop in the bottom of the inning to replace Perdomo and Tim Tawa entered the game to play first base. — ABC News, 6 Sep. 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