Island discovered by Magellan
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">island discovered by magellan</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for guam that I've seen before include "Largest of the Mariana Islands" , "NW Pacific island with large US base" , "North Pacific island, base for the US navy and air force" , "Island in the West Pacific" , "US island east of the Philippines" .)