Nuns (7)
I believe the answer is:
sisters
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">nuns</span>' is the definition.<br/ ><span class="explanation-format__explanation">(nuns often use the title 'sister')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sisters that I've seen before include "Nuns' titles" , "Patient attention required from such" , "Family relatives" , "Aunts may be" , "Female siblings" .)