Fruit agent abused in Vietnam? (6)

I believe the answer is:

orange

I'm a little stuck... Click here to teach me more about this clue!

'fruit' is the definition.
(orange is a kind of fruit)

I cannot understand how the rest of the clue works.

(Other definitions for orange that I've seen before include "Type of fruit from which bergamot comes" , "Dutch royal house" , "shade" , "stocking filler" , "Citrus fruit; colour" .)

I've seen this clue in The Sun.

Want a hint initially instead of a full solution? Install my app