Game to don legwear this person's possibly returned for a fee (7)
I believe the answer is:
hostage
'this person's possibly returned for a fee' is the definition.
The definition suggests a singular noun which matches the answer.
'game to don legwear' is the wordplay.
'game' becomes 'tag' (children's playground game).
'to don' means one lot of letters goes inside another (don can mean to wear).
'legwear' becomes 'hose' (I've seen this in another clue).
'tag' inserted within 'hose' is 'HOSTAGE'.
Can you help me to learn more?
(Other definitions for hostage that I've seen before include "One caught" , "Person held by kidnappers" , "person captive to fortune" , "Captive held for ransom" , "One held as security" .)