Noteworthy gesture (6)
I believe the answer is:
signal
This clue is a double definition.
'noteworthy' is the first definition.
(I've seen this before)
'gesture' is the second definition.
(I've seen this before)
(Other definitions for signal that I've seen before include "Gesture of communication" , "Nonverbal action or gesture that encodes a message" , "Notable; warning sign" , "Sign that conveys a message" , "Indication or warning" .)