Overpower some trespasser perhaps, getting upended (7)
I believe the answer is:
repress
'overpower' is the definition.
Although both the answer and definition are verbs in their base form, I don't see how they can define each other.
'some trespasser perhaps getting upended' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'upended' shows that the letters should be reversed in order (in a down clue, letters go up).
'sserper' is hidden within 'trespasser perhaps getting'.
'sserper' written backwards gives 'REPRESS'.
Can you help me to learn more?
(Other definitions for repress that I've seen before include "Restrict freedom of" , "Put in irons, maybe" , "Check" , "Subdue" , "Silence" .)