Pierce with a horn; blood (4)
I believe the answer is:
gore
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">pierce with a horn</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">blood</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(gore means blood or violence)</span><br/ ><br/ ></span>
(Other definitions for gore that I've seen before include "Spilt blood" , "Blood on a piece let into a garment?" , "Pierce or wound with a horn or tusk" , "Clotted blood" , "Blood; stab with tusk" .)