it's to nod your head
action
cue
It is called a 'cue'. It is the last line of the preceding actor.
When he forgot a line he would pat his belly.
ran his fingers through his hair
Giving a line to an actor is prompting.
a line that suggests movement or action?
Actor from Dallas
To prompt an actor is to give him his next line when he has forgotten it.
Script
When the input signal to a transmission line is terminated by its characteristic impedance then the signal gets absorbed in the terminating impedance itself and is not reflected back along the line. Thus, no standing waves are produced in the transmission line.
What does the zigzag line warning signal on Renault megane scenic mean