The former name of Thailand (4)
I believe the answer is:
siam
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">the former name of thailand</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for siam that I've seen before include "old-style country" , "The King and I nation" , "old part of East" , "Former name of Thailand" , "Thailand's former name" .)