squadron
Dictionarysquad ·ron (skwÃ…?d'rÉâ„¢n)
n.
A naval unit consisting of two or more divisions of a fleet.
An armored cavalry unit subordinate to a regiment and consisting of two or more troops.
A cavalry or armored unit of a European army, corresponding to a company.
A basic tactical air force unit, subordinate to a group and consisting of two or more flights.
A multitude or horde: "Squadrons of flies like particles of dust danced up and downâ ? (T.E. Lawrence).
[Italian squadrone, augmentative of squadra, squad. See squad.]
courtesy of answers.com
I cannot find any mention as to Engineers first coining the word but it is clearly a military formation. it would be between Army and Navy who first used the term since Airforce came much later.
And adding to this post, i just found this right after posting.
squadron
A Squadron is a grouping of aircraft, naval vessels, armoured fighting vehicles or soldiers.
An air force, army aviation or naval aviation squadron typically consists of three or four flights, with a total of 12 to 24 aircraft, depending on aircraft type and air force. In the Imperial Japanese Army in the Second World War, three air squadrons were assigned to each air regiment. Some air forces (including the Royal Air Force and United States Air Force) also use the term for a ground unit.
An armoured (and formerly a horsed cavalry) squadron typically consists of four or five troops. In the United States Army, a squadron is the Armor Branch equivalent of a battalion of infantry or artillery; in the British Army, it is the counterpart of an infantry company or an artillery battery.
In Britain, the designation is also used for company-sized units in the Special Air Service, Royal Engineers, Royal Corps of Signals, Royal Army Medical Corps and Royal Logistic Corps, and formerly of the now defunct Royal Corps of Transport, as well as some units in the Royal Marines.
A naval squadron is a more ad hoc grouping. The only requirement for a grouping of ships to be a squadron, is that at least two must be capital ships (battleships, battlecruisers, cruisers, or aircraft carriers). In the United States Navy, several ships of a similar type, such as submarines and destroyers, are administered as squadrons.
cheers
PV