Early video game (4)
I believe the answer is:
pong
'early video game' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pong that I've seen before include "Niff" , "Ping's regular partner?" , "Stench" , "In slang, a real stink" , "Horrid smell (informal)" .)