Encourages good health (6)
I believe the answer is:
cheers
I believe this clue is a double definition.
'encourages' is the first definition.
(cheering is a kind of encouraging)
'good health' is the second definition.
(both can be used as a drinks toast)
(Other definitions for cheers that I've seen before include "Comforts" , "Thank you; goodbye!" , "Good health!" , "Skoal! Thanks! Goodbye!" , "Praises < eggs on" .)