Depressant (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">depressant</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that depressant can be written as downer)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for downer that I've seen before include "Sedative" , "Depressing experience" , "Informally a depressant drug" , "In slang, a depressant drug" , "tranquilliser" .)
(Other definitions for dampener that I've seen before include "Moist kind of depressant?" , "muffler" , "Something that depresses - or moistens" , "killjoy" , "A thing that deadens" .)