Country junkie periodically grabs shower (7)
I believe the answer is:
ukraine
'country' is the definition.
(Ukraine is a country)
'junkie periodically grabs shower' is the wordplay.
'periodically' indicates alternate letters (letters must be selected 'every so often').
'grabs' indicates putting letters inside.
'shower' becomes 'rain' (rainfall).
The alternating letters of 'junkie' are 'uke'.
'uke' enclosing 'rain' is 'UKRAINE'.
(Other definitions for ukraine that I've seen before include "Neighbour of Russia" , "Country to the north of the Black Sea" , "Country neighbouring Russia" , "Country of eastern Europe" , "European republic" .)