Studying prolix rambles in English (9)
I believe the answer is:
exploring
'studying' is the definition.
'prolix rambles in english' is the wordplay.
'rambles' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'english' becomes 'eng'.
'prolix' anagrammed gives 'xplori'.
'xplori' going within 'eng' is 'EXPLORING'.
(Other definitions for exploring that I've seen before include "Investigating (an area)" , "Searching unknown territory" , "Searching or travelling for discovery" , "Travelling in unknown territories" , "Travelling in unknown territory" .)