A large number of (4)
I believe the answer is:
many
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a large number of</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 many that I've seen before include "multitude" , "Several" , "Numerous" , "A lot of" , "A great number" .)