Pierce with a horn (4)
I believe the answer is:
gore
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pierce with a horn</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 gore that I've seen before include "Poetic blood from Al?" , "Pierce with horn - blood" , "Showing guts" , "it's a queasy sight" , "Make a hole in" .)