Name one who is contemptuous about part of the UK (8)
I believe the answer is:
monicker
'name' is the definition.
'one who is contemptuous about part of the uk' is the wordplay.
'one who is contemptuous' becomes 'mocker'.
'about' indicates putting letters inside.
'part of the uk' becomes 'ni' (Northern Ireland).
'mocker' enclosing 'ni' is 'MONICKER'.
(Other definitions for monicker that I've seen before include "Name (sl)" , "Nickname (slang)" , "Handle" , "Name or nickname" .)