Fruit of round variety beginning to smell (7)
I believe the answer is:
oranges
'fruit' is the definition.
(oranges are a type of fruit)
'round variety beginning to smell' is the wordplay.
'round' becomes 'o' (o is a circular letter).
'variety' becomes 'range' (range can mean a wide variety).
'beginning to' says to take the initial letters.
The initial letter of 'smell' is 's'.
'o'+'range'+'s'='ORANGES'
'of' acts as a link.
(Other definitions for oranges that I've seen before include "Citrus fruit" , "a zesty lot" , "They are not the only fruit, wrote Jeanette Winterson" , "Gear son up for fruit" , "'Mandarins, say (7)'" .)