Although friendly, a chap fibbed (6)

I believe the answer is:

allied

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'although friendly a' is the definition.
I can't judge whether this definition defines the answer.

'chap fibbed' is the wordplay.
'chap' becomes 'al'.
'fibbed' becomes 'lied' (I've seen this before).
'al'+'lied'='ALLIED'

Can you help me to learn more?

(Other definitions for allied that I've seen before include "Joined together for a purpose" , "Joined for mutual benefit" , "United through treaty" , "Joined by, eg, treaty" , "in concert" .)

I've seen this clue in the Evening Standard.

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