Advance payment craftsman tentatively pockets (4)
I believe the answer is:
ante
'advance payment' is the definition.
(I've seen this in another clue)
'craftsman tentatively pockets' is the wordplay.
'pockets' indicates the answer is hidden within the clue (pocket can mean to contain).
'ANTE' is hidden in the letters of 'craftsman tentatively'.
(Other definitions for ante that I've seen before include "Initial contribution to the common pot" , "Hoofed mammal" , "advance payment" , "Player's stake in poker - a ten? (anag)" , "Prefix meaning before" .)