Carnal (6)
'carnal' is the definition.
(I know that carnal can be written as animal)
This is all the clue.
(Other definitions for animal that I've seen before include "Neither vegetable nor mineral" , "Uncivilised person" , "Creature having voluntary movement" , "Animate being" , "savage" .)
'carnal' is the definition.
(thesaurus)
This is all the clue.
(Another definition for sexual that I've seen is " Lax use (anag.)".)