Entertain mature prisoner providing security (7)
I believe the answer is:
hostage
'security' is the definition.
(I've seen this before)
'entertain mature' is the wordplay.
'entertain' becomes 'host' (hosting is a kind of entertaining).
'mature' becomes 'age' (synonyms).
'host'+'age'='HOSTAGE'
'prisoner providing' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for hostage that I've seen before include "One seized as security" , "Prisoner held as security" , "Person taken as security" , "One held for ransom" , "Person held by kidnapper for ransom" .)