Cognisant, mindful (5)
I believe the answer is:
aware
This clue is a double definition.
'cognisant' is the first definition.
(similar in meaning)
'mindful' is the second definition.
(I've seen this in another clue)
(Other definitions for aware that I've seen before include "Acquainted with or conscious of" , "well informed" , "Cognisant, mindful" , "fly" , "Conscious, knowing about" .)