Sturdy, strapping (5)
I believe the answer is:
burly
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sturdy</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">strapping</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that strapping can be written as burly)</span><br/ ><br/ ></span>
(Other definitions for burly that I've seen before include "Beefy" , "Big and sturdy" , "Stocky" , "Sturdily built" , "Strongly and heavily built" .)