German found out, and complained (8)
I believe the answer is:
grumbled
'complained' is the definition.
(grumbling is a kind of complaining)
'german found out' is the wordplay.
I cannot quite see how this works, but
'german' could be 'g' (abbreviation) and 'g' is located in the answer.
The remaining letters 'rumbled' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
'and' acts as a link.
Can you help me to learn more?
(Other definitions for grumbled that I've seen before include "Complained in a bad-tempered way" , "Expressed discontent" .)