Old people going round large shrine (6)
I believe the answer is:
oracle
'shrine' is the definition.
(I know that oracle is a type of shrine)
'old people going round large' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'people' becomes 'race' (people can mean a national group or race).
'going round' means one lot of letters goes inside another (some letters go around others).
'large' becomes 'L' (eg in clothes sizes).
'race' going around 'l' is 'racle'.
'o'+'racle'='ORACLE'
(Other definitions for oracle that I've seen before include "Ancient Greek expounder of wisdom" , "Wise words" , "Someone of great wisdom" , "Holy place in ancient times where gods prophesied" , "Source of divine advice" .)