Existence; vitality (4)
I believe the answer is:
life
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">existence</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(being alive)</span><br/ ><br/ >'<span class="explanation-format__original">vitality</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for life that I've seen before include "Animation" , "Maximum stretch?" , "Vitality, vigour" , ""But an empty dream" (Longfellow) - "As tedious as a twice-told tale" (Shakespeare)" , "Baffin oiler (anag) - 7 film" .)