Drone (3)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">drone</span>' is the definition.<br/ ><span class="explanation-format__explanation">(drone can mean to make a humming sound)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for hum that I've seen before include "Drone - stink" , "Sing with the mouth shut" , "Smell strongly" , "Make musical sound with closed lips" , "Sound of busy activity" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">drone</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 idler that I've seen before include "Laggard" , "Layabout, loafer" , "One resting" , "Lazybones; gear wheel" , "Couch potato" .)