Negative out of ignorance (3)
I believe the answer is:
nor
'negative' is the definition.
('nor' is an example of a negative)
'out of ignorance' is the wordplay.
'out of' indicates a hidden word.
'NOR' is hidden in the letters of 'ignorance'.
(Other definitions for nor that I've seen before include "And not either" , "Common conjunction, goes with neither" , "Word paired with "neither"" , "Conjunction meaning 'and not'" , "Neither one ... the other" .)