It's "Truck Cum Ground Kit", otherwise known as the "Truck and Ground Station".
I'm sure I have a post-WW2 C.E.S. for something like that (but far simpler than the "you can fit this to just about anything except a tank" Canadian version).
The non-slang meaning of 'cum' is from the Latin meaning 'with' and tends to mean 'combined with' in English. e.g. 'garage cum workshop' (it's used as both) or 'cum laude' - 'with honours' as a university graduation which is all Latin.
So basically it's the extremely comprehensive kit shown in the Canadian Working Instructions for the WS19 that can be fitted (Just!) into a wireless truck but also taken out and used as a ground station.
The meaning that gets blocked for obscenity is considerably more recent.
Chris.
