Rich, say: odd million invested in wine that's brought over (7)
I believe the answer is:
drummer
'rich say' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'odd million invested in wine that's brought over' is the wordplay.
'odd' becomes 'rum' (rum can mean strange or dubious).
'million' becomes 'm' (abbreviation).
'invested in' is an insertion indicator.
'wine' becomes 'red' (red is a type of wine).
'that's brought over' is a reversal indicator.
'red' written backwards gives 'der'.
'rum'+'m'='rumm'
'rumm' going within 'der' is 'DRUMMER'.
Can you help me to learn more?
(Other definitions for drummer that I've seen before include "Someone who keeps 18 [RHYTHM]" , "eg Ringo" , "Gene Krupa, say" , "One beating" , "player among the percussion" .)