Fluster; rattle
I believe the answer is:
faze
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fluster</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">rattle</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(both can mean to bother or unsettle)</span><br/ ><br/ ></span>
(Other definitions for faze that I've seen before include "Throw from" , "Shake" , "Disturb, disconcert" , "Unsettle - perturb" , "Put off" .)