Is able to (3)
I believe the answer is:
can
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">is able to</span>' is the definition.<br/ ><span class="explanation-format__explanation">(if you can do something you are able to do it)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for can that I've seen before include "sack from abroad" , "prison" , "May" , "Container (e.g. beer)" , "Metallic container" .)