Support good queen going about old city keeping dry (8)
I believe the answer is:
buttress
'support' is the definition.
(buttress is a kind of support)
'good queen going about old city keeping dry' is the wordplay.
'good queen going' becomes 'bess' (I can't explain this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'old city' becomes 'ur' (ancient city state).
'keeping' means one lot of letters goes inside another.
'dry' becomes 'tt' (abbreviation for teetotal).
'ur' enclosing 'tt' is 'uttr'.
'bess' enclosing 'uttr' is 'BUTTRESS'.
Can you help me to learn more?
(Other definitions for buttress that I've seen before include "Reinforce" , "She-goat" , "that goes flying round the cathedral?" , "Stanchion" , "Support built against a wall, prop" .)