Barter, exchange (5)
I believe the answer is:
trade
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">barter</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">exchange</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(trading is a kind of exchanging)</span><br/ ><br/ ></span>
(Other definitions for trade that I've seen before include "Barter, do business" , "Commercial exchange of goods and services" , "job" , "groundsman?" , "Buying/selling of goods" .)