Primitive drive (6)
I believe the answer is:
libido
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">primitive drive</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 libido that I've seen before include "Psychic, sexual, energy" , "Sexual drive" , "lust!" , "Emotional craving" , "Emotional energy associated with sexual desire" .)