Gerrunder - a regional pronunciation of "get under", as shouted by Pamela Tatler throughout her entire fourth year.
She once made a teacher so frustrated by her persistent one-word outbursts that he picked up her, her chair and her desk in one scooping movement, and put her outside the class.
After he deposited her outside the door and returned to the class, everyone went quiet. The calm was punctuated by a plaintive question from outside;
"Gerrunder?"
This was an innovation; she'd never punctuated her gerrunders before, and a new range of Gerrunder Moods was born.
A : Have you heard the gestapo joke?
b : No...
(A slaps B hard around the around the face and shouts in a comedy Nazi accent)
A : Liar!
If the question is answered with a weary "Yes", then slap them and call them a liar anyway; disorientation is a perfectly valid method of interrogation.
Get down on it. Suck my helmet. Please don't bite it. Just excite it. Get your lipstick. Round my dipstick.. It just ends there. It feels like it shouldn't, but it does.
Getting a legger involved a group of you standing a small distance (no more than 15-20 metres) from a group of "older boys" who were busy doing something else (usually playing football), and hurling abuse at them in order to provoke them into chasing you (obviously with the intention of beating you senseless). You then all just had to run like fuck and get away.

The older boys didn't know what the fuck we were doing or why and I don't think we did either.
Monumentally stupid game, annoyingly however I lost the rules. It involved asking older kids to beat you up until they did, though.
The ingenious practice of insulting people inaccurately. The insultee will invariably correct the insult, thus confirming and accepting it.

Person A: "You're a fuckwick"
Person B: "You mean I'm a fuckWIT"
Person A: "Yeah, you are"

Hilarity will, inevitably, ensue.
A peculiar fashion that developed toward the end of fourth year, this was the height of daring, although as most of the time was spent sitting down it wasn't too difficult. When you were stood up there were always people in front of you to hide you. Four or five of us did it once but we had to stop because we were making some others giggle insanely. Tom Baird once walked out to the front of Modern Studies and stood smiling at the teacher with his cock out. The teacher only looked mildly disgruntled so eventually Baird just wandered out of the room, still swinging free.
Pronounced gugunubuh - stands for 'gay ginger nature boy'. Applies to anyone attempting to sing back to some birds, if they are ginger. In particular, my brother.
In our primary school we formed 'The Ghost Gang' based on our suspicions that the school was haunted. In reality we were more like the SS than the Ghostbusters because our only purpose was to kick the shit out of diabetics, vegetarians and asthmatics.
Every primary school in the land is actually haunted, usually by dead children who were killed when an unstable playground wall fell on them, although sometimes it's a dreadful fire which engulfed the building in Victorian times.

Bizarrely, a simple wall fall will often result in several gruesome ghosties, whereas the school itself burning down will always leave just one rather dull (and mute) dead girl wearing a dirty white dress who Jenny swears was watching her in the toilets at break.
Hampshire, Winter. An elite team of boarding school pupils gather on the headmster's lawn and build an enormous giant snow cock on this forbidden land. It was huge; as tall as the tallest pupil you can imagine.
The next day, it became a natural meeting point before school, and pupils lined the forbidden lawn, gazing in wonder at the edifice. The headmaster sent out a weedy, natural victim of a teacher with instructions to take down this obscenity.
His limbs, flapping uselessly at the proud, mighty totem served only to whip the baying crowd of pupils into hysteria, who saw it as nothing less than an attempt to wank it off.
Cocktail supplied by Martin Gibbs consisting of a drop from each bottle of his father's sizeable drinks cabinet with the balance made up with cooking sherry. The bulk of the cocktail was generally given to anyone who had PE that afternoon and the subsequent displays of ridiculous drunken excess would have resulted in stern disiplinary action had our PE teacher not been a habitual alcoholic himself. Gibbs Suprise also led to the incapacitation of our cross country team - the only thing for which our school was famed. Thus I like to think it played a small part in the school's collapse into the very bottom of the league tables.
Gilbert was the groundskeeper at the school and as such lived in a shed between the pavilion and the cricket-scoring hut. (it was a middle class school in surrey that had pretensions towards some sort of Brideshead revisited idyll).
Naturally it was assumed that he molested children in the shed. Anyone suspected of kiddy fiddling was known as a Gilbert.
Medieval farmer with an unfortunate affliction. We first became aware of his existence when, for some reason, some first years in History had been made to write letters from one medieval farmer to another, and the best of these had been pinned to the wall. Hilarity ensued when we noticed that one of them concluded with, "PS. Giles, you still HIV positive?"
Whenever a policeman comes to school (either to talk to you about careers and shit, or to arrest someone, depending on the calibre of your school), it is customary to point them out to a ginger, exclaiming "Ooh, someone hasn't paid their ginger tax!"

The ginger in question is then expected to reply "Damn, I knew I forgot something", and then spend the rest of the day in hiding. If he doesn't do this, you may hit him.
As a male child of the rusty-follicled persuasion, I learned that the worst thing you can possibly do is try and deflect insults with a cry of "It's not ginger! It's strawberry blonde!"

Thanks for the tip, Ross. Log, you could do worse than take heed.

Derived from the overpriced service station pasty and sandwich makers. It is to be caught with your dick in your hand. Perhaps with a pasty in the other hand.
The box in games, full of spare clothes. This is used by three sets of people; fat or feeble kids who wilfully forget their kit to avoid games, trevors who can't afford their own kit, and normal children who simply forgot it was games. These are perhaps the most unfortunate group; because the gippo box is never laundered, the poor normal child will be forced to run around in fat kid's ball sweat and poor kid's fleas.
If a girl touches you, or even accidentally brushed past you, you may become quite hysterical and shout "girl disease! girl disease!". It is then necessary to touch the nearest boy, and jeer "Girl disease tick - one nil" at him. I have no idea what girls thought about this game/ritual.
There is a time of life when everyone writes down the names of all the girls in the year and then award points for their key features. Attributes such as "breasts", "arse" and "face" were all judged and graded. We also had a category for whether she was a slag or not - higher points obviously awarded for slags. We kept our top trump chart fairly quiet, but by the time it had been handed down to my brother's year, they actually drew individual cards for each girl, had them laminated and would then sit and play "Girl Top Trumps" in the middle of the class each lunchtime.
Is it me or was my school the only one where girls wrapped themselves up in skipping ropes and behaved like horses, or did this madness exist elsewhere? The guys at my school never really understood what was going on.
At my school one girl would be the horse, with the skipping rope tied round her, and another would 'ride' her, running along behind holding the handles.

So the game pretty much consisted of running, and I had no idea there was anything wrong with selling videos of it to sweaty old men.
Tell a fit but dim girl that only girls can touch their elbows together behind their backs. If she tests this, she will push her chest out, thereby providing the watching boys with their daily ration of cheapies.

Don't bother asking flat-chested girls, no matter how fit or dim they are. Wait until 6th form when they'll probably have caught up.
French for "lodging" or "resting place". If found on a blackboard, a single rapid swipe transforms the word easily into "git". It helps phonetically if you remove the circumflex, but I'm a busy man with many blackboards to tend to.
Something I shouldn't have shouted when Mr Dhondy walked into the room.