A few more offerings:
Piece or Frog - Ticket
Ching - Fare
Effing it - Travelling without a ticket
Area F - Alternative term for Effing it - As in an Area F Rover
Effer - Person travelling without a ticket or trespassing on the railway
Lamp - Spotter standing on the end of a platform (resembling a lamppost)
Nedex - Railtour, i.e. a service for Neds
Popex - Specials that ran to York when the pope came to visit
Ethex - Saga specials (Carrying Ethels, i.e. elderly people)
Kettlex - A steam-hauled excursion
Mystex - An excursion where the destination is unknown (except to people with gen!)
Caped - A service that is terminated prior to reaching its destination, or that is cancelled entirely
Cupboard - Class 153
Bendy bus - Classes 141/2/3/4
Turd - Class 142 in original brown livery
Generator - 47401-47420 (fitted with generators rather than alternators)
Wagon - Class 46
Dub-dub - Class 50
Fish - Class 81 (With picture of a fish on the side)
Flower pot - Class 03 with an exhaust resembling a flower pot
Small Engine - Classes 26 & 27
Tram - HST
Bog unit / bog cart / charriot - 1st generation DMU
Scud - Class 158
Set of vacs - Rake of Vacuum braked coaching stock
Compos - Compartment coaching stock
Drag - An electric train being hauled by a diesel locomotive
Nought-nought - A zero minute connection between services, aka Dead Connection
Minus 10 - When the train you are hoping to catch is due to depart 10 minutes before the train you are currently on is due to arrive (other negative numbers are also available)
Plus 10 - As above, but a positive connecting time (other positive numbers re also available) - can also be applied to the the time remining to get back from the pub/chip shop/etc. in order to catch your train
Bail - get off a train
Flagged - To have not caught a train (i.e. you flagged it off)
Fagged - A train that has broken down
Cloth caps - Barnsley to Scarborough service
The Coast - Newcastle to Darlington (and reverse) via Sunderland sleeper portion, which later became a loco-hauled connecting service with no sleepers
The Hole - The sidings next to the old Platform 10 at Newcastle Central
Chuck out turn - Service for which the loco diagram was something of a lottery
Bowled, bowled out or withered - To miss a train you really wanted to travel on, have a loco not turn up on the expected service, or any other general form of disappointment when out bashing
NB Season - The summer months when locomotives without train heat supply (i.e. Non Boilered) were permitted to work pssenger services
Scratched - To have travelled behind a previously required locomotive
Cleared - To have travelled over 1,000 miles behind a given locomotive
Overdoss - To miss your stop due to being asleep
Gen merchant - Person who was able to supply information on which locomotives were working which trains (usually someone with access to TOPS)
Duff gen - Incorrect information pertaining to the above
F1.7 at 10 years - Attempting to take a photograph in very challenging light conditions
Up midnight / Down midnight - The Paddington - Penzance sleeper services
Every lamppost - The stopping pattern of an all stations service
Insect - A certain type of annoying enthusiast
Slops house - Facility for buying tea on a station (back in the days prior to Costa Coffee, etc.)
The Blocks - Kings Cross (or other terminus station)
Throughout - Travelling on a train from its point of origin to its final destination (if the latter is a terminus then you could "Do it to The Blocks")