Pierce top of skin on fruit (5)
I believe the answer is:
spear
'pierce' is the definition.
(thesaurus)
'top of skin on fruit' is the wordplay.
'top of' indicates taking the first letters.
'on' means one lot of letters go next to another.
'fruit' becomes 'pear' (pear is a kind of fruit).
The first letter of 'skin' is 's'.
's'+'pear'='SPEAR'
(Other definitions for spear that I've seen before include "Weapon to throw" , "asparagus for example" , "Long pointed weapon" , "Sharp weapon" , "Asparagus shoot" .)