Oppose? Yes, among other things (6)
I believe the answer is:
resist
'oppose?' is the definition.
(resisting is a kind of opposing)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for resist that I've seen before include "'Withstand, fight against (6)'" , "turn down" , "Take stand against, oppose" , "Put up fight, oppose forcefully" , "Offer opposition to" .)