Core; courage (5)
I believe the answer is:
heart
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">core</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that core can be written as heart)</span><br/ ><br/ >'<span class="explanation-format__original">courage</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that heart is a type of courage)</span><br/ ><br/ ></span>
(Other definitions for heart that I've seen before include "Spirit - core" , "Cardiac courage" , "Body organ" , "show enthusiasm" , "Vital organ - centre - courage" .)