There weren't many, but (not counting abbreviated names) my contribution is...
Bug-Cart = ANY Diesel Multiple unit (Other bods called them BOG-CARTS)
Skinhead = A Class 24 with NO roof headcode box
Jinty = a Fowler 3F (that's a steam loco, for the benefit of some of you young 'uns!)
Semi = Stanier's "Princess Royal" Class, e.g. 46201
Streak = Gresley A4
Tadpole = a particular 3-car Deisel-Electric Multiple unit on the Southern region. Apparently, one of the end coaches was noticeably bigger than the other two.
Crab = a Fowler(?) 5MT (42501?) - so-called because of its cylinder link motion.
Big 8 = Stanier 8F
Cheesebox = Met-Vick Co-Bo (e.g. D5703)
43106