Admit on one occasion about starting German domain (7)

I believe the answer is:

concede

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'admit' is the definition.
(I know that concede is a more specific form of admit)

'on one occasion about starting german domain' is the wordplay.
'on one occasion' becomes 'once' (synonyms).
'about' is an insertion indicator.
'starting german domain' becomes 'cde' (I can't justify this - if you can you should give a lot more credence to this answer).
'once' inserted inside 'cde' is 'CONCEDE'.

Can you help me to learn more?

(Other definitions for concede that I've seen before include "Admit; yield" , "Yield; grant" , "Admit; surrender" , "Acknowledge - abandon" , "Surrender, yield" .)

I've seen this clue in The Daily Express.

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