Clans (6)
I believe the answer is:
tribes
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">clans</span>' is the definition.<br/ ><span class="explanation-format__explanation">('tribe' can be a synonym of 'clan')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tribes that I've seen before include "Social groups in traditional societies" , "races" , "Groups of people related by blood" , "Communities of primitive or nomadic groups" , "Groups of families in traditional societies" .)