Great service (3)
I believe the answer is:
ace
I believe this is a double definition.
'great' is the first definition.
(ace can informally mean very good)
'service' is the second definition.
(ace is a kind of service)
(Other definitions for ace that I've seen before include "unit > of highest quality" , "Hole in one; card" , "Top card or champion" , "Outstanding" , "Crack" .)