Where does “bull session” come from?

bull session (English) comes from English session, from Middle English session, from Old French session, from Latin sessiō, from Latin -tiō, from Latin dissertātiō, from Latin dissertus, from Latin disserere — small stone, pebble; gravel, rubble.

bull session (English): An informal discursive group discussion, often one where politics, economics or current events are discussed

Definitions

  1. An informal discursive group discussion, often one where politics, economics or current events are discussed

Ancestry of “bull session”, step by step

bull session traces back through two separate lines of ancestry.

via English session

StepLanguageWordMeaning
1EnglishsessionA period devoted to a particular activity, e.g....
2Middle Englishsession
3Old Frenchsessionsitting; session
4Latinsessiōa sitting
5Latin-tiōtion, -ation, -ing
6Latindissertātiō(spoken) dissertation, discourse, disquisition
7Latindissertusarranged, disposed; explained
8Latindissereresecond-person singular future passive indicative...
9Latindis-asunder, apart, in two; reversal, removal;...
10Latincalceusshoe
11Latincalxlimestone; chalk; the finish line
12Ancient Greekχάλιξsmall stone, pebble; gravel, rubble

via English Bull

StepLanguageWordMeaning
1EnglishBullThe constellation and zodiacal sign Taurus
2Middle Englishbullfalsehood
Every word from Ancient Greek χάλιξ