Being simply whacked, unable to avoid defeat (6)
I believe the answer is:
beaten
'being simply whacked unable to avoid' is the definition.
I can't tell whether this defines the answer.
'defeat' is the wordplay.
I cannot quite see how this works, but
'defeat' could be 'beat' (beating is a kind of defeating) and 'beat' is present in the answer.
The remaining letters 'en' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for beaten that I've seen before include "Well-trodden" , "Defeated or overcome" , "Thrashed or whisked" , "Struck; defeated" , "Defeated - whipped" .)