Age of the neo Nazis? (3)
I believe the answer is:
eon
'age' is the definition.
(I know that eon is a type of age)
'of the neo nazis?' is the wordplay.
'of' indicates the answer is hidden within the clue.
'EON' is hidden within 'neo nazis'.
(Other definitions for eon that I've seen before include "Very long period (US and technical spelling)" , "billion years" , "Major division of geological time" , "Long period of time" , "thousand million years" .)