Make cross hand gesture (5)
I believe the answer is:
bless
'gesture' is the definition.
(blessing is a kind of gesturing)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bless that I've seen before include "Approve of" , "Wish happiness" , "Give benediction" , "Pray for" , "Invoke divine favour on" .)