Hard hit (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">hard hit</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for blow that I've seen before include "Cuff" , "Strong current of air" , "Shock; sound (a horn)" , "Bang, wallop" , "Sudden misfortune" .)