Heedful, observant (9)
I believe the answer is:
attentive
I believe this clue is a double definition.
'heedful' is the first definition.
(synonyms)
'observant' is the second definition.
(similar in meaning)
(Other definitions for attentive that I've seen before include "Listening closely" , "Dutiful" , "Alert; observant" , "Showing courtesy to another, or alert" , "Taking notice" .)