Member has pounds, investing one million (4)
I believe the answer is:
limb
'member' is the definition.
(member can mean a limb)
'pounds investing one million' is the wordplay.
'pounds' becomes 'lb' (abbreviation for the unit of weight).
'investing' means one lot of letters goes inside another (inserted letters are taken in or invested).
'one' becomes 'i' (Roman numeral).
'million' becomes 'm' (abbreviation).
'i'+'m'='im'
'lb' enclosing 'im' is 'LIMB'.
'has' is the link.
(Other definitions for limb that I've seen before include "Arm, leg or wing" , "arm, perhaps" , "Large tree branch" , "A supporter" , "Branch - arm - leg" .)