Heir, male child, around Channel Islands (5)
I believe the answer is:
scion
'heir' is the definition.
(I've seen this in another clue)
'male child around channel islands' is the wordplay.
'male child' becomes 'son' (I've seen this before).
'around' indicates putting letters inside.
'channel islands' becomes 'CI'.
'son' going around 'ci' is 'SCION'.
(Other definitions for scion that I've seen before include "Branch" , "Offspring" , "Young shoot/twig" , "Plant shoot; descendant of a noble family;" , "Young twig; descendant" .)