Wary, careful (5)
I believe the answer is:
chary
I believe this is a double definition.
'wary' is the first definition.
(synonyms)
'careful' is the second definition.
(similar in meaning)
(Other definitions for chary that I've seen before include "Cautious, wary" , "Careful" , "Cautiously reluctant" , "cagy" , "Circumspect" .)