Wartime prisoner meeting monarch might (5)
I believe the answer is:
power
'might' is the definition.
(being mighty)
'wartime prisoner meeting monarch' is the wordplay.
I cannot really understand how this works, but
'prisoner' could be 'pow' (POW is an example) and 'pow' is found within the answer.
'monarch' could be 'er' (abbreviation for Elizabeth Regina, British Queen) and 'er' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for power that I've seen before include "What may be measured in watts" , "Control and influence exercised over others" , "Ability (to do something)" , "military force" , "See 12" .)