Sign, mark (5)
I believe the answer is:
token
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sign</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that token is a type of sign)</span><br/ ><br/ >'<span class="explanation-format__original">mark</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that token is a type of mark)</span><br/ ><br/ ></span>
(Other definitions for token that I've seen before include "Sign, symbol or an evidence" , "empty gesture?" , "Symbolic; voucher" , "Something of sentimental value" , "Symbol; metal disc" .)