Angel wearing singlet, gold (8)
I believe the answer is:
investor
'angel' is the definition.
(I've seen this before)
'wearing singlet gold' is the wordplay.
'wearing' becomes 'in' (in jeans or in a dress).
'singlet' becomes 'vest' (synonyms).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'in'+'vest'+'or'='INVESTOR'
(Other definitions for investor that I've seen before include "One with stocks/shares" , "One putting money into financial scheme" , "angel" , "market trader?" , "he speculates" .)