Poland's leader has craving for expulsion (5)
I believe the answer is:
purge
'for expulsion' is the definition.
(an expulsion is a purge or removal)
'poland's leader has craving' is the wordplay.
'leader' indicates taking the first letters.
'has' is a charade indicator (letters next to each other).
'craving' becomes 'urge' (I've seen this in another clue).
The initial letter of 'polands' is 'p'.
'p'+'urge'='PURGE'
(Other definitions for purge that I've seen before include "Get rid of unwanted elements" , "Remove impurities from" , "Atone for offence or get rid of" , "empty bowels" , "Removal by cleansing" .)