Outrageous old woman drained nurses (8)
I believe the answer is:
flagrant
'outrageous' is the definition.
(flagrant can mean outrageous or blatant)
'old woman drained nurses' is the wordplay.
'old woman' becomes 'gran' (short for grandmother).
'drained' becomes 'flat' (I am not sure about this - if you are sure you should believe this answer much more).
'nurses' means one lot of letters goes inside another (nurse can mean to hold onto or harbour).
'gran' put within 'flat' is 'FLAGRANT'.
Can you help me to learn more?
(Other definitions for flagrant that I've seen before include "'Conspicuous, glaring (8)'" , "Barefaced" , "Of unconcealed outrageousness" , "Patent" , "notorious" .)