Large heavy knife (7)
I believe the answer is:
machete
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">large heavy knife</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for machete that I've seen before include "The mace (anag.)" , "Teach me with large jungle knife" , "Heavy knife used as weapon" , "Jungle chopper" , "Large heavy knife for cutting vegetation" .)