Poor mortals not right? Not quite! (6)
I believe the answer is:
almost
'not quite' is the definition.
(I've seen this before)
'poor mortals not right?' is the wordplay.
'poor' indicates an anagram.
'not' indicates named letters should be taken away.
'right?' becomes 'r' (abbreviation).
'mortals' with 'r' removed is 'motals'.
'motals' with letters rearranged gives 'ALMOST'.
(Other definitions for almost that I've seen before include "As good as" , "Nearly, not quite" , "practically" , "Not entirely" , "Not totally" .)