Basque separatist group (3)
I believe the answer is:
eta
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">basque separatist group</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eta that I've seen before include "when it might reach us?" , "Greek letter - time due (abbr)" , "Greek character?" , "European separatists, initially" , "Foreign letter" .)