Origin

This character combines two simpler pictures: a mouth (口) and something in the middle or center (中). The idea is of something piercing straight through the middle—like when you thread food onto a stick and poke it through the center, it goes in one side and out the other, the way a skewer passes through a row of items. The vertical line running down the middle of the character visually reinforces this sense of something going straight through. Over time, this image of piercing or threading became the character's main meaning, which is why it means skewer or spit.