Payload (5)
I believe the answer is:
cargo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">payload</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that payload can be written as Cargo)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for cargo that I've seen before include "This taken on board" , "Baggage" , "Stuff on board" , "Hold contents" , "What gets carried" .)