Orifice

Noun

1. A mouth or aperture, such as of a tube, pipe, etc.; an opening.

   "the orifice of an artery or vein; the orifice of a wound; he entered the cave's gaping orifice"

2. One of the natural external openings of the human or animal body.

   "the vagina and other orifices"

3. A stupid or objectionable person.