Move to invest pounds, running club (8)
I believe the answer is:
bludgeon
'club' is the definition.
(synonyms)
'move to invest pounds running' is the wordplay.
'move' becomes 'budge' (budging is a kind of moving).
'to invest' means one lot of letters goes inside another (back).
'pounds' becomes 'L' (L can represent the monetary pound).
'running' becomes 'on' (I've seen this in other clues).
'budge' going around 'l' is 'bludge'.
'bludge'+'on'='BLUDGEON'
(Other definitions for bludgeon that I've seen before include "Hit with a heavy club" , "Club used maliciously" , "Blunt instrument" , "Cudgel" , "Thick club" .)