Cryptic clue about northern relative (5)
I believe the answer is:
uncle
'relative' is the definition.
(I know that relative can be written as uncle)
'cryptic clue about northern' is the wordplay.
'cryptic' indicates anagramming the letters (a cryptic or obscure order of the letters).
'about' means one lot of letters goes inside another.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'clue' with letters rearranged gives 'ucle'.
'ucle' enclosing 'n' is 'UNCLE'.
(Other definitions for uncle that I've seen before include "one who's taken the pledge" , "Pawnbroker (sl.)" , "Dad's brother" , "Law enforcement body" , "Slang name for pawnbroker" .)