Famous boxer with boy or girl (6)
I believe the answer is:
alison
'girl' is the definition.
(girl's name)
'famous boxer with boy' is the wordplay.
'famous boxer' becomes 'ali' (I've seen this in another clue).
'with' means one lot of letters go next to another.
'boy' becomes 'son' (male child).
'ali'+'son'='ALISON'
'or' is the link.
(Other definitions for alison that I've seen before include "Girl's name" , "woman" , "female" , "lady" , "Girl" .)