Wordless agreement (3)
I believe the answer is:
nod
'wordless agreement' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nod that I've seen before include "Indicate assent with head movement" , "Gesture of agreement" , "It's said to be as good as a wink" , "slight bow" , "Cain was banished to the land of ..." .)