Set upon (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">set upon</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 assail that I've seen before include "Attack, lash out" , "Attack violently and persistently" , "storm" , "Go for" , "Criticise severely" .)
(Other definitions for attack that I've seen before include "Go on the offensive" , "Act violently against or criticise strongly" , "Launch an offensive" , "Assault, offensive" , "storm" .)