Apposite, appropriate (3)
I believe the answer is:
apt
I believe this is a double definition.
'apposite' is the first definition.
(synonyms)
'appropriate' is the second definition.
(synonyms)
(Other definitions for apt that I've seen before include "Suitable or likely" , "suitable for the circumstances" , "Having a tendency" , "Fit, suitable" , "Tending" .)