Excavating (6)
I believe the answer is:
mining
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">excavating</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 mining that I've seen before include "Excavating (ores)" , "Extracting ore etc. from the earth" , "Extracting ores or coal from the earth" , "non-renewable industry" , "Excavating (coal, ore)" .)