Conscious of a town in Herts (5)
I believe the answer is:
aware
'conscious of' is the definition.
(being conscious means being aware of something)
'a town in herts' is the wordplay.
'town in herts' becomes 'ware' (I am not sure about this - if you are sure you should believe this answer much more).
'a'+'ware'='AWARE'
Can you help me to learn more?
(Other definitions for aware that I've seen before include "Knowing (of something)" , "Acquainted with or conscious of" , "Acquainted with or mindful of" , "well informed" , "Alert, conscious of" .)