Great in number (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">great in number</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for legion that I've seen before include "Host" , "Large unit of the old Roman army" , "Roman military formation" , "Many soldiers" , "Roman military body of men" .)
(Other definitions for multitudinous that I've seen before include "Profuse" , "Occurring in great numbers" , "Large numbers" , "Very many in number" .)