More gems of finnish military jargon:

Bemari
A Beemer. A fond nickname for any of the BMP series of Infantry Fighting Vehicles.
Elso (or Eltso)
"Elektroninen Sodankäynti" or Electronic Warfare. If any communications equipment fails to work, for any reason, it can be jocularly attributed to Elso: "Eltsoo ilmassa" (lit. "electronic warfare in the air"). Can be used for other equipment failures also, if you have a suitably surrealistic sense of humour.
GTJ
"Gonalla Tänään Jäljellä." You use this instead of TJ when you consider yourself a Gona, or -- if you have a good sense of humour -- in a satirical sense when you are a Läjä.
Härö
A person who does a lot of Härvääminen. See Härvätä.
Häröillä
Synonym for Härvätä.
Häröpallo
A person who is Härö. Also any random unorganized group of soldiers -- most often a group that should be organized. Soon to be reprimanded by their superiors.
Jumppaputki
"The Exercise Tube." The French-manufactured APILAS 112 mm disposable anti-tank rocket launcher (Finnish military designation 112 RsKes), weighing in at 9 kg -- hence the nickname.
Tornari
Synonym for Tornihuhu.
Tuliasemakahvi
Insanely strong black coffee brewed in the Böhe during war games. Good for those long nights manning the Kösseli.
VP
"Vapautus Palveluksesta." Means that you don't have to perform any duties at all -- and are not allowed to do anything else either. You are basically restricted to your bed. Also, one of the dreaded leave-killers... if the doctor gives you VP, VUP, or VPO for the weekend, you are stuck, and some poor corporal will have to stay behind and watch you (unless you get admitted to the Veksi).
VPO
"Vapautus Palveluksesta lukuunottamatta Oppitunteja." The only duties you have to perform are attending classes. One of the leave-killers.
Zilton
Officially ZIL-131, a 3,5 ton truck manufactured by the AMO ZIL Company of Russia. To my knowledge, only used by the Panssariprikaati (The Armored Brigade). Typically these trucks have been in storage lots for so long, their wheels have lost their round shape, resulting in some... interesting gyrations when the truck hits 100 kph -- which, by the way, is pretty close to its maximum. I have personally been on a Zilton that was doing 110 kph. It is not a moment fondly recalled. A Zilton is reputedly powered by an engine that's almost an exact copy of a small-block V8... except that it is a mirror image. Apparently someone botched while developing spy photographs.
A Zilton will traverse almost any terrain, thanks to its tires having adjustable pressure. You can, for example, almost totally empty them, and -- so the tornihuhu goes -- drive it straight through a swamp.
If, for some reason, you get to sleep in a Zilton (e.g. by being extremely sneaky), you can refer to it as "staying at the Hotel Zilton."
Ärva
Pea soup. Served every tuesday, along with pancakes. Rumour has it (or more appropriately, there's a tornihuhu saying that) the cooks put whole cows in it. The size of the chunks of unidentifiable meat-like substance floating in the kettles is quite intimidating, to be sure.