Do away with — undergrowth (5)
I believe the answer is:
scrub
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">do away with</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">undergrowth</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(scrub can mean undergrowth or vegetation)</span><br/ ><br/ ></span>
(Other definitions for scrub that I've seen before include "Rub hard with a brush" , "Drop" , "Cancel (colloq)" , "Get rid of" , "Rub hard; brushwood" .)