Samuel Johnson first defined crossfire as
"The crossing of two curmudgeons, mostly to be avoided."
However, the term quickly lost this meaning when it was mistakenly omitted from the 1755 publication of "A Dictionary of English Language" when the original manuscript was smeared a bit by a sweaty young typesetter working in the employment of William Strahan during the final steps of printing.
All was not lost, though, as the term soon reappeared in the early 1800's in a transcript written by Private Peter McMullen of the 27th Regiment of Foot who described the Battle of Waterloo. In his transcripts he quoted many of the French infantry as shouting "crossfire" as the Prussians napalmed the lot of 'em. However, linguists have accurately pointed out there is no French word “crossfire” and a more accurate quote may in fact be "Le gros feu!" meaning "Fat fire" which would obviously be a reference to the ensuing Prussians napalm attack, or, as others have suggested, and when yelled very loudly by a malnourished Frenchmen, a plea to “burn the 'fat guy' instead of me!”
Say "Fetter Kerl" or else
The actual word or phrase the doomed infantry men shouted and it's meaning has been a hot bed of debate and controversy for historians and linguists alike. A well known German historian and philogist in the late 1800's, Theodore Mommsen, was a proponent of the "fat guy" theory to the disapproval of many of his French born colleagues. Occasionally, friendly disagreements would escalate into shouting matches which ended with Dr. Mommsen secret "Mommsen headlock" manoeuvre where his opponent would remain immobilized until the German words "fetter Kerl" (fat guy) were uttered for all to hear.
Ted Turner recycled the term "crossfire" as a memoriam to Napoleon Bonaparte and his troops dying battle cry and used it as the title of a weekly television show on CNN showcasing two curmudgeons which was mostly ignored by American TV viewers and loved by the French. The show was abruptly cancelled when Jon Stewart ate co-host Tucker Carlson. Over |20 Million viewers tuned in to see the event happen live. The show's other three hosts, Paul Begala, James Carville and Robert Novak were let go after the show was cancelled, or "crossfired". The stress of losing his job made Novak go crazy and he later exploded on another CNN program. His greasy remains still smear the set of the Situation Room; week after week of toothpaste applications still fail to remove the stains.