Why a note goes astray in transit (2,3,3)
I believe the answer is:
on the way
'in transit?' is the definition.
(I've seen this before)
'why a note goes astray' is the wordplay.
'goes astray' is an anagram indicator.
'why'+'a'+'note'='whyanote'
'whyanote' with letters rearranged gives 'ON THE WAY'.
(Other definitions for on the way that I've seen before include "In progress" , "In transit" , "About to arrive" , "En route" .)