Vernal equinox month (5)
I believe the answer is:
march
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">vernal equinox month</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 march that I've seen before include "Stride; month" , "Parade" , "Military walking style" , "Journey undertaken by army etc" , "Walk smartly" .)