Seventh letter in the Greek alphabet (3)
I believe the answer is:
eta
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">seventh letter in the greek alphabet</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 "Militants" , "character abroad?" , "Greek H" , "Greek letter - time due (abbr)" , "Foreign letter" .)