Clitoris

Courtesy of Wikimedia Commons

The clitoris, generally referred to just as "the clit", is a small elongated erectile organ at the anterior part of the vulva, and is homologous with the penis. It contains millions of nerve endings and is highly reactive to stimulation.

Often when women speak of having their clitoris pierced they are actually refering to a clitoral hood piercing — which can be done either as a horizonal hood piercing or vertical hood piercing, and not to an actual clitoral piercing, which is quite rare.