Concerning notice your leader prepared (5)
I believe the answer is:
ready
'prepared' is the definition.
(associated in meaning)
'concerning notice your leader' is the wordplay.
'concerning' becomes 're' (both can mean on a particular topic).
'notice' becomes 'ad' (short for advert).
'leader' says to take the initial letters.
The first letter of 'your' is 'y'.
're'+'ad'+'y'='READY'
(Other definitions for ready that I've seen before include "Willing (to do something); cash" , "Suitably prepared" , "for immediate use" , "Prepared, willing" , "Available now" .)