Boy led astray (3)
I believe the answer is:
del
'boy' is the definition.
'led astray' is the wordplay.
'astray' indicates an anagram.
'led' with letters rearranged gives 'DEL'.
(Other definitions for del that I've seen before include "Derek (dim.)" , "drew it" , "Mathematical symbol < , delegate" , "- Boy (Only Fools and Horses)" .)