Irritant (4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">irritant</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 pest that I've seen before include "Destructive insect or other animal" , "Troublesome person" , "Annoying creature" , "Disease with a high death rate" , "Destructive insect or nuisance" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">irritant</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that irritant can be written as thorn)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for thorn that I've seen before include "Old Norse character" , "Spiny bush" , "Spine - prickle - Old English runic letter" , "Sharp point on a shrub" , "problematic point" .)