Communicate non-stop (7)
I believe the answer is:
express
I believe this clue is a double definition.
'communicate' is the first definition.
(expressing is a kind of communicating)
'non-stop' is the second definition.
(I've seen this before)
(Other definitions for express that I've seen before include "Put into words - quick!" , "Fast - state - train" , "Utter - direct" , "Verbalize" , "Transport" .)