Book collection (7)
I believe the answer is:
library
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">book collection</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 library that I've seen before include "Supply of reading material" , "building with works that are shelved?" , "Book archive" , "Bibliotheca" , "Book room" .)