Flatten with a club (4)
I believe the answer is:
iron
This clue is a double definition.
'flatten' is the first definition.
(I know that iron is a more specific form of press)
'club' is the second definition.
(type of golf club)
'with a' is the link.
(Other definitions for iron that I've seen before include "Club; element" , "Flatten; element" , "stern" , "Heavy metallic element" , "A magnet attracts it" .)