Isolated as Man United? (5)
I believe the answer is:
alone
'isolated' is the definition.
(similar in meaning)
'man united?' is the wordplay.
'man' becomes 'al' (man's name).
'united?' becomes 'one' (as in a phrase like 'we are one').
'al'+'one'='ALONE'
'as' acts as a link.
(Other definitions for alone that I've seen before include "Isolated from others" , "without another" , "Note of charges" , "unique" , "Solo" .)