The word came to English in 1871, meaning a dance, party, or lively gathering. It appears to have come from the word shindy, a spree or merrymaking. Though nobody is certain, shindy may have come from a hockey-like Scottish game named shinty or the Old English word scinu, meaning shin.
A party wasn’t called a bash until some time after 1901. This sense of bash grew out of an earlier slang expression meaning a drunken spree. Before that, bash made its noun debut in 1805 meaning a heavy blow after a long run as a verb meaning to strike violently, which started in the 1640s & came from Old Norse.
An informal gathering of folk musicians has been known as a hootenanny since 1940. Before that, the word hootenanny meant any sort of gadget, & before that a hootenanny was more specific -- the sort of gadget a car thief uses to break into a car.
The 1932 meaning of rally, a gathering of automobile enthusiasts, comes from an earlier military meaning of rally, a regrouping for renewed action after a repulse, which came to English in the 1650s from the French word rallier, to unite again or reassemble.
The word jamboree is a bit of a puzzle. It’s been in use in English since 1866, meaning large gathering. Some etymologists think it may have come from the French word bourree, a rustic dance. Others suggest it may have Hindu roots. Some note that the term jambone was used in the game of cribbage when a player held the highest five cards available. No definitive assemblage of documents has surfaced to solve this puzzle.
When blowout first came to English in 1825 in meant a brewhaha or outburst. Since then blowout has come to mean an abundant feast or festive social affair. Blowout is constructed from blow, which comes from an Old English term meaning to move air combined with out, another Old English word meaning out, outside or without.
The word powwow, which today means council, conference or meeting, is an Algonquian word that initially meant shaman, Indian priest or medicine man. It comes from a word that meant to use divination, to dream. In the 1660s among English speakers it began to mean magical ceremony among natives, which led to its modern meaning.
A confab is a gathering of people for discussion. This term is a shortening of confabulation, a 1400s English word meaning talking together. Its root is the Latin word confabulari.
What do youhave to say about all these various words meaning a gathering?
And big thanks to the two-person crowd of Anne R. Allen & Christine Ahern for suggesting the terms tilting, shock, & erasing to my growing list of archidioms.