Fake British sauce for spag bol sent back (5)

I believe the answer is:

bogus

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

'fake' is the definition.
(I know that fake can be written as bogus)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for bogus that I've seen before include "Dummy" , "that's not real" , "Phoney, not genuine" , "Fake, sham" , "Sham, counterfeit" .)

I've seen this clue in The Independent.

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