Contrarily takes on ravines, perhaps (7)
I believe the answer is:
reviews
'contrarily takes' is the definition.
Although both the answer and definition are verbs in their -s form, I don't see how one could define the other.
'on ravines perhaps' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'ravines perhaps' becomes 'views' (I can't justify this - if you can you should give a lot more credence to this answer).
're'+'views'='REVIEWS'
Can you help me to learn more?
(Other definitions for reviews that I've seen before include "Surveys" , "critical periodicals?" , "Critiques" .)