Pester, bother (6)
I believe the answer is:
harass
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">pester</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">bother</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that harass is a type of bother)</span><br/ ><br/ ></span>
(Other definitions for harass that I've seen before include "Vex - persecute" , "Nag" , "Intimidate, torment" , "Continually torment" , "Constantly intimidate" .)