Pierces first of season's fruits (6)
I believe the answer is:
spears
'pierces' is the definition.
(I know this)
'first of season's fruits' is the wordplay.
'first of season' becomes 's' (1st letter of 'season').
'fruits' becomes 'pears' (pear is a kind of fruit).
's'+'pears'='SPEARS'
(Other definitions for spears that I've seen before include "Javelins" , "Long weapons with a sharp points" , "pop singer" , "stickers" , "Pointed poles as weapons" .)