Bid; volunteer (5)
I believe the answer is:
offer
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">bid</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that bid can be written as offer)</span><br/ ><br/ >'<span class="explanation-format__original">volunteer</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that volunteer can be written as offer)</span><br/ ><br/ ></span>
(Other definitions for offer that I've seen before include "Present for acceptance or rejection" , "hand" , "Attempt" , "Propose (to give)" , "Tender for acceptance" .)