Try a little discernment (5)
I believe the answer is:
taste
I believe this is a triple definition!
'try' is the first definition.
(I know that try can be written as taste)
'a little' is the second definition.
(thesaurus)
'discernment' is the third definition.
(having discernment is having good taste)
(Other definitions for taste that I've seen before include "Show sense" , "Delicacy" , "eat only the smallest amount" , "Sensation in the mouth caused by food" , "A sense; briefly sample" .)