Gives fish a manual greeting (9)
I believe the answer is:
handshake
'a manual greeting' is the definition.
'handshake' can be an answer for 'greeting' (I've seen this before). I am not sure about the 'a manual' bit.
'gives fish' is the wordplay.
'gives' becomes 'hands' ('hand' can be a synonym of 'give').
'fish' becomes 'hake' (type of fish).
'hands'+'hake'='HANDSHAKE'
Can you help me to learn more?
(Other definitions for handshake that I've seen before include "Gesture of greeting or of agreeing a deal" , "Form of greeting" , "Conventional sort of manual greeting" , "acknowledgment" , "Conventional greeting of manual kind" .)