Receive and look after a long time prisoner (7)

I believe the answer is:

hostage

I'm a little stuck... Click here to teach me more about this clue!

'prisoner' is the definition.
(someone taken as a prisoner)

I cannot understand how the remainder of the clue works.

(Other definitions for hostage that I've seen before include "One seized as security" , "Prisoner held as security" , "Person held by kidnappers" , "One held as security" , "Person held by kidnapper for ransom" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app