Resident in Hampshire briefly entertaining a little (10)
I believe the answer is:
inhabitant
'resident' is the definition.
(I've seen this before)
'in hampshire briefly entertaining a little' is the wordplay.
'hampshire' becomes 'hants' (postal abbreviation).
'briefly' means to remove the last letter.
'entertaining' is an insertion indicator.
'a little' becomes 'abit' (synonyms).
'hants' with its final letter taken off is 'hant'.
'hant' going around 'abit' is 'habitant'.
'in'+'habitant'='INHABITANT'
(Other definitions for inhabitant that I've seen before include "One who stays in" , "One living in a place" , "One occupying a place" , "Resident" .)