Rod will give the signal (3)
I believe the answer is:
cue
I believe this is a double definition.
'rod' is the first definition.
(I've seen this before)
'the signal' is the second definition.
(as in an actor's cue)
'will give' is the link.
(Other definitions for cue that I've seen before include "strike" , "Billiard stick - hint - signal" , "Snooker player's stick" , "Signal to begin - tapered stick" , "On a car[D?] this would give a prompt" .)