No reversal — keep waiting for connection (2,4)
I believe the answer is:
'waiting for connection' is the definition.
(I've seen this before)
'no reversal keep' is the wordplay.
'reversal' is a reversal indicator.
'keep' becomes 'hold' (both can mean to have or possess something).
'no' reversed gives 'on'.
(Other definitions for on hold that I've seen before include "waiting to come in" , "not through yet?" , "Made to wait (on phone)" , "Delayed -- postponed" , "In abeyance" .)