Wind direction indicator (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wind direction indicator</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for vane that I've seen before include "The weather-cock sounds conceited" , "Part of a weathercock" , "Turbine blade" , "Wind pointer" , "Blade of a propeller" .)