Hint concerning bodyguard (8)
I believe the answer is:
reminder
'hint' is the definition.
(thesaurus)
'concerning bodyguard' is the wordplay.
'concerning' becomes 're'.
'bodyguard' becomes 'minder' (I've seen this in other clues).
're'+'minder'='REMINDER'
(Other definitions for reminder that I've seen before include "Memento" , "Knot in handkerchief?" , "note" , "Memory jogger" , "Aide-mmoire" .)