The Oxford English Dictionary defines a bun-fight as:
a jocular expression for a tea-party
The OED gives a single quote, from 1928, which uses the words wayzgoose and Eisteddfod and is thus not very helpful, even after one looks up those words.
At the other end of the scale (erudition or stuffiness, take your pick), The Urban Dictionary defines bun-fight as:
A sustained, overblown argument about a petty matter, usually personal
in nature to the participants but not to everyone else.
According to WiseGEEK, the origin may be in the late 19th century, and the term can mean either a formal event, a large party or a petty argument.
There is perhaps a difference in British and US usage.
World Wide Words offers an explanation of the origin as Victorian children squabbling over buns and cakes at teatime, but has no back-up evidence. Expressions and Sayings says much the same as World Wide Words.
Although everything the above sources say sounds reasonable, does anyone have evidence of the origin of the phrase and evidence of how it came to have such disparate meanings?
Finally, towards the end of the comments on another, unrelated question, one of ELU's most erudite gurus offers as a hypothesis that
It derives from disputes between antagonists who are both hot and
cross.
???
Best Answer
The term bun fight is evidently widely used across nations of the old British Commonwealth and goes back to the late 1800s.
'Bun fight' in slang dictionaries
The traditional meaning of bun fight appears in a glossary entry in Hippocrene Language and Travel Guide to Britain (1996):
Jonathon Green, The Dictionary of Contemporary Slang (1984) offers a bit of a twist on that definition:
This suggests a fight over buns rather than with buns.
Ann Barr & Peter York, The Official Sloane Ranger Handbook: The First Guide to What Really Matters in Life (1982) explicitly takes issue with the Oxford English Dictionary with regard to the term's meaning, though why we should believe Barr & York is not entirely clear:
Norman Schur, British English A to Zed: A Definitive Guide to the Queen's English (2013) takes a more demure line:
Eric Partridge manages to multiply the difficulty by finding ten additional terms to grapple with. First from Partridge, Dictionary of Slang and Unconventional English, second edition (1938):
his edition of Partridge also has an entry for bun-struggle or bun-worry:
And then from Partridge, Dictionary of Slang and Unconventional English, eighth edition (1984):
So that brings the jocular variants on a tea-party theme to a crooked baker's dozen (bun-beat, bun-feast, bun-fight, bun-struggle, bun-worry, crumpet-scramble, muffin-fight, muffin-worry, tea-fight, tea-scramble, and tea-shine).
'Bun fight' in the wild
Limiting the inquiry to the bun-based terms, I find these early specimens. From William Black, Wild Eelin: Her Escapades, Adventures & Bitter Sorrows (1898):
From "Temperance at Shahjehanpur," in The Thin Red Line: The Regimental Paper of the 2d Batt., (Princess Louise's) Argyll & Sutherland Highlanders (April 1899):
From Lilian Quiller-Couch, "The Love Affairs of Patricia—I Try to Amuse Cousin George" in The Saturday Evening Post, volume 174 (1901):
From "The Library Press" in The Library World: A Medium of Intercommunication for Libraries (February 1902):
From "Stray Shots from Solomon," in The Canadian Shoe and Leather Journal (May 1905):
'Bun fight' as trouble
When bun fight came to mean (figuratively) a spat, dispute, or other conflict is difficult to identify with specificity, but it certainly had that meaning in "Bun Fight Over a Sex Book," in the [Sydney, New South Wales] Bulletin (1980) [combined snippets]:
From Australian Government Publishing Service, Proceedings of the Conference, volume 1 (1982) [combined snippets]:
And from Northern Ireland Assembly, Official Report of Debates, issue 4 (1982):
None of these later instances seem to be referring to tea parties—at least not pleasant ones. But almost certainly the later meaning derives from the earlier "tea-party" meaning, and seems to entail a social gathering gone wrong.
The sense of "bun fight" as a specifically legal or procedural tiff finds support in Export Today, volume 11 (1995) [combined snippets]:
From Aboriginal Law Journal (1995) [combined snippets]:
And from Barbara Farbey, David Targett & Frank Land, Hard Money, Soft Outcomes: Evaluating and Managing the IT Investment (1995):
Later instances of the term suggest that conflicts may be distinguishable into "legal bun fights" and "political bun fights." But whatever the antagonistic possibilities of bun fight in its modern slang senses, the traditional slang sense persists as well. From Rhys Bowen, A Royal Pain (2008):
Conclusions
A bun fight can mean simply a tea party—as it has for more than a century. Or (in more-recent decades) it can mean a dispute over social proprieties, legal rights, or political power. One common characteristic of these various meanings is the suggestion that the gathering goes on rather longer than the participants might wish.
The earliest of the bun-related terms for tea party may be bun-worry; at any rate it is the earliest such term to appear in a Google Books search. From "Sketches of Irish Life," in Once a Week (November 16, 1872, and December 7, 1872):
Unquestionably, people invited to tea have been worrying, feasting, struggling, beating, and fighting with buns for a very long time.