Join hands? (4)
I believe the answer is:
clap
'join hands?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for clap that I've seen before include "Sudden loud noise (of thunder?)" , "Applaud in manual way" , "Strike hands together to applaud" , "A meeting of hands" , "Audibly show approval" .)