Remarkable gesture (6)

I believe the answer is:

signal

This clue is a double definition.

'remarkable' is the first definition.
(thesaurus)

'gesture' is the second definition.
(thesaurus)

(Other definitions for signal that I've seen before include "Notable; warning sign" , "Indicate" , "Memorable" , "important to train drivers > striking" , "Communication that encodes a message" .)

I've seen this clue in The Times and The Telegraph.

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