Pirate upset splitting share getting sent home (12)
I believe the answer is:
repatriation
'getting sent home' is the definition.
(being returned to one's home country)
'pirate upset splitting share' is the wordplay.
'upset' indicates anagramming the letters.
'splitting' means one lot of letters goes inside another (some letters split a word into two).
'share' becomes 'ration' (a ration is a share of a limited resource).
'pirate' is an anagram of 'epatri'.
'epatri' put within 'ration' is 'REPATRIATION'.
(Other definitions for repatriation that I've seen before include "Sending home" , "The returning of someone to their own country" .)