Hand-to-hand contact (4)
I believe the answer is:
clap
'hand-to-hand contact' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for clap that I've seen before include "A meeting of hands" , "Audibly show approval" , "Applaud manually" , "express approval" , "Applaud in manual way" .)