Childminder removing top for duke? Boy! (5)
I believe the answer is:
danny
'boy' is the definition.
(boy's name)
'childminder removing top for duke?' is the wordplay.
'childminder' becomes 'nanny' (someone who looks after children).
'removing top' means to remove the first letter (I've seen 'removes top' mean this).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'duke?' becomes 'd' (abbreviation).
'nanny' with its first letter removed is 'anny'.
'anny' put after 'd' is 'DANNY'.
(Other definitions for danny that I've seen before include "Boy, Kaye or Blanchflower" , "- Kaye, US actor" .)