Fireplace floor (6)
I believe the answer is:
hearth
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fireplace floor</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 hearth that I've seen before include "part of furnace" , "Floor of a fireplace in the home" , "cosy setting" , "fireside feature" , "suitable place for a fire" .)