Nothing good with respect to giant (4)
I believe the answer is:
ogre
'giant' is the definition.
(I've seen this before)
'nothing good with respect to' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'good' becomes 'g' (abbreviation).
'with respect to' becomes 're' (I've seen this in other clues).
'o'+'g'+'re'='OGRE'
(Other definitions for ogre that I've seen before include "Giant who eats people" , "Giant of folklore who ate humans" , "Giant: monster" , "Wicked and inhuman person" , "Terrifying person" .)