Negative (3)
(Other definitions for nor that I've seen before include "In addition, not" , "Common conjunction, goes with neither" , "And not either" , "Conjunction meaning 'and not'" , "Link word" .)
'negative' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for not that I've seen before include "Word of negation" , "It negates a word" , "In no way, never" , "Having close-cut hair" , "Negation of what follows" .)