Mark over some German vowels (6)
I believe the answer is:
umlaut
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mark over some german vowels</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for umlaut that I've seen before include "German accent" , "Mark indicating changed vowel value in German" , "Dots over vowel, as in Koln" , "Diacritical mark (two dots) placed over a vowel in German to indicate a change in sound" , "Mark put over a vowel in German to indicate a different quality" .)