Quick of mind; well-informed (11)
I believe the answer is:
intelligent
I believe this is a double definition.
'quick of mind' is the first definition.
(I've seen this before)
'well-informed' is the second definition.
(I know that well-informed can be written as intelligent)
(Other definitions for intelligent that I've seen before include "Bright, quick of mind" , "Reasoning; alert" , "displaying brainpower" , "Capable of reason" , "quick on the uptake" .)