Rural infection almost a severe pain (7)
I believe the answer is:
bucolic
'rural' is the definition.
('bucolic' can be similar in meaning to 'rural')
'infection almost a severe pain' is the wordplay.
'infection' becomes 'bug'.
'almost' means to remove the last letter (most of the word but not all of it).
'a severe pain' becomes 'colic' (I've seen this before**).
'bug' with its last letter taken away is 'bu'.
'bu'+'colic'='BUCOLIC'
(Other definitions for bucolic that I've seen before include "Characteristic of country life" , "Pastoral poem" , "Of rural or pastoral life" , "Rustic - pastoral" , "Agrarian" .)