Fill up again (9)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fill up again</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 replenish that I've seen before include "Stock up again" , "Restock, refill" , "Fill up again, say glass with drink" , "Help siren (anag) - make up" , "Replace" .)