Enclosure with soldier guarding hospital entrance (7)
I believe the answer is:
enchant
'entrance' is the definition.
(to entrance is to enchant or bewitch)
'enclosure with soldier guarding hospital' is the wordplay.
'enclosure' becomes 'enc' (abbreviation as in letters).
'with' is a charade indicator (letters next to each other).
'soldier' becomes 'ant' (soldier is a type of ant).
'guarding' is an insertion indicator.
'hospital' becomes 'h' (abbreviation for hospital on maps).
'enc'+'ant'='encant'
'encant' going around 'h' is 'ENCHANT'.
(Other definitions for enchant that I've seen before include "Appeal" , "Fascinate - delight" , "Captivate, charm" , "Delight or bewitch" , "Beguile" .)