Burn the midnight oil
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">burn the midnight oil</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 study that I've seen before include "Read: den" , "Den; closely look at" , "Den - learning" , "Writing-room" , "Examine carefully" .)