Very active (4)
'very active' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for on the go that I've seen before include "ready to start monopoly?" , "Active, in constant motion" , "Active and energetic" , "Always busy" , "Ever busy" .)
'very active' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for busy that I've seen before include "Active, occupied" , "Pot plant" , "Fully employed" , "Sedulous" , "detective" .)
(Another definition for buzzing that I've seen is " very excited".)