Smudge, stain (4)
I believe the answer is:
blot
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">smudge</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">stain</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that stain can be written as blot)</span><br/ ><br/ ></span>
(Other definitions for blot that I've seen before include "Ink stain; disgrace" , "Smudge of ink" , "Don't do it to your copybook" , "Spot of ink, paint etc" , "Smudge (on escutcheon?)" .)