Way later, I would add something to attract attention (4)
I believe the answer is:
psst
'something to attract attention' is the definition.
I can't judge whether this definition defines the answer.
'way later i would add' is the wordplay.
I cannot really see how this works, but
'way' could be 'st' (short for street) and 'st' is found within the answer.
'add' could be 'ps' and 'ps' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for psst that I've seen before include "Beckoning sound" , "Surreptitious attention-seeker" , "Sibilant sound to attract attention furtively" , "attempt to make secret contact" , "This is confidential" .)