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

Meantime, right-hander Nick Pivetta (flexor) threw a bullpen on Sunday and will resume a minor league rehab assignment on Tuesday with low Single-A Lake Elsinore at Rancho Cucamonga. — Jeff Sanders, San Diego Union-Tribune, 25 Aug. 2026

And in yet another call from the 2025 playbook, Sasaki is expected to go to the bullpen to mirror his September return from injury last season. — Doug Padilla, Oc Register, 24 Aug. 2026

The Miami Marlins shook up their bullpen a bit on Sunday, designated for assignment veteran lefty reliever John King and recalling rookie Jack Ralston ahead of their series finale against the Washington Nationals. — Jordan McPherson, Miami Herald, 23 Aug. 2026

Andrew Benintendi drove in the other run with a double and Chicago's bullpen allowed one run in seven innings. — ABC News, 23 Aug. 2026

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