Additionally second person said, it’s needless (5)
I believe the answer is:
undue
'needless' is the definition.
(I've seen this before)
'additionally second person said it's' is the wordplay.
'additionally' becomes 'und' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'second person' becomes 'you' (second person pronoun).
'said' indicates a 'sounds like' (homophone) clue.
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'you' is a homophone of 'u'.
'und'+'u'+'e'='UNDUE'
Can you help me to learn more?
(Other definitions for undue that I've seen before include "Not to be paid" , "Excessive amount" , "Not warranted" , "Beyond normal limits" , "Improper" .)