Shrub over slope, climbing rose perhaps (8)
I believe the answer is:
oleander
'shrub' is the definition.
(I've seen this before)
'over slope climbing rose perhaps' is the wordplay.
'over' becomes 'o' (cricket abbreviation).
'slope' becomes 'lean' (I've seen this before).
'climbing rose perhaps' becomes 'der' (I can't explain this - if you can you should believe this answer much more).
'o'+'lean'+'der'='OLEANDER'
Can you help me to learn more?
(Other definitions for oleander that I've seen before include "Flowering plant" , "No dealer in evergreen shrub" , "Evergreen flowering shrub from olden era" , "Reloaned for evergreen shrub with bright flowers" , "Poisonous shrub, also called rosebay" .)