Perhaps Fritz is returning gesture (6)
I believe the answer is:
signal
'gesture' is the definition.
(thesaurus)
'perhaps fritz is returning' is the wordplay.
'perhaps fritz' becomes 'lang' (Fritz Lang).
'returning' is a reversal indicator.
'lang'+'is'='langis'
'langis' written backwards gives 'SIGNAL'.
(Other definitions for signal that I've seen before include "Message in the form of a gesture" , "Notable; warning sign" , "Gesture or object giving information" , "Important; gesture" , "thing followed by train driver?" .)