Red spirit, say, turning up rarely at first (6)
I believe the answer is:
ginger
'red' is the definition.
'spirit say turning up rarely at first' is the wordplay.
'spirit' becomes 'gin' (alcoholic spirit).
'say' becomes 'eg' (both can mean 'for example').
'turning up' shows that the letters should be reversed in order.
'at first' indicates taking the first letters.
The first letter of 'rarely' is 'r'.
'eg' back-to-front is 'ge'.
'gin'+'ge'+'r'='GINGER'
(Other definitions for ginger that I've seen before include "Red (of hair)" , "This 13 [SPICE]" , "Spicy root, often served with sushi" , "Hot-tasting root or general liveliness" , "Light reddish colour or hot-tasting flavour" .)