Tellingbone 

It is from a 70s children's tv series called Catweasel. The eponymous character is a wizard who is surprised by 'modern' technology like the electric light bulb "sun in a bottle" and the telephone "telling bone"

Answer the tellingbone will you please? My hands are in the washing up water.

Tellingbone by DeepSpin July 4, 2016

Tellingbone 

TELEPHONE.

Self explanatory.

I believe this is a mainly Aussie expression in rhyming slang, but may be used within the sound of the bell (cockney-ism).

"Get him on the tellingbone".

Tellingbone by Dave Sheedy September 3, 2006

Tellington

A person who is anonymous to many, but if told, it could cause serious problems for all stoners

Dick: "Hey, did you tell Tellington?"
Stoner: "Na."

Tellington by blacktits420 January 27, 2015