Where does “bullpen” come from?

Bullpen comes from English bull and pen, with bull descending through Middle English and Old English from Proto-Indo-European bʰel-, meaning to swell.

bullpen (English): An enclosed area used to hold bulls; An enclosed...

Definitions

  1. An enclosed area used to hold bulls; An enclosed...

Ancestry of “bullpen”, step by step

bullpen traces back through two separate lines of ancestry.

via English pen

StepLanguageWordMeaning
1EnglishpenAn enclosure used to contain domesticated...
2EnglishpenetrationThe act of penetrating something; Specifically,...
3Middle Englishpenetracioun
4Old Frenchpenetracïonpenetration (act, instance of penetrating)
5Latinpenetrātiōpiercing, penetration
6Latin-tiōtion, -ation, -ing
7Latindissertātiō(spoken) dissertation, discourse, disquisition
8Latindissertusarranged, disposed; explained
9Latindissereresecond-person singular future passive indicative...
10Latindis-asunder, apart, in two; reversal, removal;...
11Latincalceusshoe
12Latincalxlimestone; chalk; the finish line
13Ancient Greekχάλιξsmall stone, pebble; gravel, rubble

via English Bull

StepLanguageWordMeaning
1EnglishBullThe constellation and zodiacal sign Taurus
2Middle Englishbullfalsehood

Words derived from “bullpen

Every word from Ancient Greek χάλιξEvery word from Latin -tiōEvery word from Latin dis-