Meg’s elder sister in carriage turning red or white? (5)
I believe the answer is:
rioja
'meg's elder sister' is the definition.
I can't tell whether this defines the answer.
'in carriage turning red or white?' is the wordplay.
'in' indicates putting letters inside.
'carriage' becomes 'air' (both can mean someone's stance or posture).
'turning' says the letters should be written in reverse.
'red or white?' becomes 'oj' (I can't explain this - if you can you should believe this answer much more).
'air' back-to-front is 'ria'.
'ria' going around 'oj' is 'RIOJA'.
Can you help me to learn more?
(Other definitions for rioja that I've seen before include "Spanish table wine" , "Open space (ancient Greek)" , "kind of red" , "it comes from grapevine" , "Dry red wine from Spain" .)