buttock

之所以回答你这个问题是估计不会有别人回答.Hip, 臀部，either side of the body below the waist and above the thigh;the ball-and-socket joint between the head of the femur and the acetabulumAss, 屁股，slang for sexual intercoursehaunch，臀部，the loin and leg of a quadruped;the hip and buttock and upper thigh in human beingsbuttock，臀部，either of the two large fleshy masses of muscular tissue that form the human rump所以，从以上英文意义可以看出来，ass，是一个与性相关的俚语，意思是爱谁谁