Not ignorant of a place in Herts (5)
I believe the answer is:
aware
'not ignorant' is the definition.
(I've seen this in another clue)
'a place in herts' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
The remaining letters 'ware' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Other definitions for aware that I've seen before include "Having knowledge or realisation" , "Having knowledge (of fact)" , "Cognizant" , "Informed; conscious" , "fly" .)