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

Palencia went on to surrender three runs in the frame, though one came on Gabriel Moreno’s check-swing that saw the ball clip first base instead of becoming the third out on a grounder to Michael Busch. — Meghan Montemurro, Chicago Tribune, 28 Aug. 2026

Pirela was signed by the Texas Rangers at age 17 out of Barquisimeto, Venezuela, and played catcher, first base and the outfield from 2009 to 2011 for the team’s Dominican Republic Summer League affiliate. — Steve Henson, Los Angeles Times, 26 Aug. 2026

Once Pratt reached first base for a single, Murphy subbed him out for a pinch runner. — Will Sammon, New York Times, 26 Aug. 2026

Otto Lopez took off from first base, looking to advance into scoring position to give Joe Mack a better opportunity to drive him in and extend the Miami Marlins’ early lead on the Boston Red Sox. — Jordan McPherson, Miami Herald, 26 Aug. 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