Money that is admitting Queen supporter (9)
I believe the answer is:
brassiere
'supporter' is the definition.
(I've seen this before)
'money that is admitting queen' is the wordplay.
'money' becomes 'brass' (I've seen this before**).
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'admitting' indicates putting letters inside.
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'ie' enclosing 'er' is 'iere'.
'brass'+'iere'='BRASSIERE'
(Other definitions for brassiere that I've seen before include "support" , "garment" , "Female undergarment supporter" .)