Town's football team dropping deep, all but one of them amateur (10)
I believe the answer is:
cheltenham
'town's' is the definition.
(town in Gloucestershire)
I cannot understand how the remainder of the clue works.
(Other definitions for cheltenham that I've seen before include "English racecourse and spa town" , "Gloucestershire racecourse" , "Gloucestershire town" , "GCHQ location" , "West Country spa town with racecourse" .)