bullpen

noun

bull·​pen ˈbu̇l-ˌpen 

also ˈbəl-

variants or less commonly bull pen

plural bullpens also bull pens

1

: a large cell where prisoners are detained until brought into court

Commonly called the "bullpen," the court lockup is behind the courtroom and is used as a holding area for prisoners …

—Bruce A. Scruton

2

a

: a place on a baseball field where pitchers warm up before they start pitching

In the bullpen, Goose Gossage is warming up.

—Tony Scherman

b

: the relief pitchers of a baseball team

After five innings Seattle led 14-2 and, with baseball's best bullpen waiting to protect the lead should starter Aaron Sele falter …

—Sports Illustrated

3

: an open work area not divided into offices

… an alternative to the traditional combination of private offices for the brass and bullpens for the workers.

—Carl Ruff

Examples of bullpen in a Sentence

Recent Examples on the Web

The club has addressed their outfield needs — with the additions of Isaac Collins and Lane Thomas — while also solidifying their bullpen this offseason. —Kansas City Star, 19 Dec. 2025

The Phillies essentially replaced Strahm in the bullpen with the righty Keller, who broke out as a high-leverage reliever with the Cubs last season. —Tom Dougherty, CBS News, 19 Dec. 2025

The Rockies, given the volatility of relievers, might be more inclined to trade from their bullpen. —Ken Rosenthal, New York Times, 17 Dec. 2025

In November, the Yankees non-tendered a handful of disappointing pitchers from their bullpen, which was far below its usual standard this season. —Jackson Roberts, MSNBC Newsweek, 11 Dec. 2025

Word History

First Known Use

1809, in the meaning defined at sense 1

Rhymes for bullpen

• again
• airmen
• amen
• culmen
• flagmen
• gunmen
• lawmen
• oilmen
• playpen
• schoolmen
• tegmen
• ben

Kids Definition

bull pen

noun

1

: a large cell where prisoners are held until brought into court

2

a

: a place on a baseball field where relief pitchers warm up

b

: the relief pitchers of a team