Company singer brought up crown (7)
I believe the answer is:
coronet
'crown' is the definition.
(I know that coronet is a type of crown)
'company singer brought up' is the wordplay.
'company' becomes 'co' (abbreviation).
'singer' becomes 'tenor' (tenor is a kind of singer).
'brought up' says the letters should be written backwards (in a down clue, letters go up).
'tenor' backwards is 'ronet'.
'co'+'ronet'='CORONET'
(Other definitions for coronet that I've seen before include "jewelled headdress" , "Small crown" , "Peer's headgear" , "mark of noble rank?" , "Simple crown" .)