Strong urge
(Other definitions for impulsion that I've seen before include "Force" , "Urge" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strong urge</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for yen that I've seen before include "change in East" , "Have a longing for Japanese money?" , "Longing (colloq.)" , "Intense longing" , "Japanese currency; yearning" .)
(Other definitions for desire that I've seen before include "Strong wish" , "Want strongly" , "Reside in longing" , "Crave" , "Want, wish for" .)