Crossword Genius

Amateur, say, upset about Blackburn callback (7)

Ross

I believe the answer is:

dabbler

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

'amateur' is the definition.
(I know that dabbler is a type of amateur)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for dabbler that I've seen before include "amateur" , "Someone with passing interest" , "Dilettante" .)

I've seen this clue in The Daily Express.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.