Nausea (8)
I believe the answer is:
sickness
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">nausea</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that nausea can be written as sickness)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sickness that I've seen before include "Ill health" , "Ailment" , "Illness, malady" , "It's not looking good" , "Illness, disease" .)