Puts his money into sleeveless garments (7)
I believe the answer is:
invests
'puts his money' is the definition.
'invests' can be an answer for 'puts' ('invest' can be a synonym of 'put'). I am not sure about the 'his money' bit.
'into sleeveless garments' is the wordplay.
'into' becomes 'in'.
'sleeveless garments' becomes 'vests' (I've seen this before).
'in'+'vests'='INVESTS'
Can you help me to learn more?
(Other definitions for invests that I've seen before include "Puts money into a venture expecting a return" , "Lays out, hoping for profit" , "Gives significance to" , "Speculates" , "Puts money into a venture in expectation of a return" .)