Surprisingly short Lord Sugar keeps you talking a lot (9)
I believe the answer is:
garrulous
'surprisingly short' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for garrulous that I've seen before include "Chatty" , "Over-talkative" , "Verbose" , "Voluble - oral gurus (anag)" , "Loquacious and voluble" .)