introitus
1. [ noun ] (anatomy,zoology) entrance or opening to a hollow organ or tube (especially the vaginal opening)
Examples:

"the introitus of the vagina"

Related terms: orifice
Similar spelling:   intromit
  indris
  intrigue
  introvert
  introject
  introduce
  intrinsic
  intriguer
  intron
  intrusive
  intrusion
  introspect
  intriguing
  intragroup
  intrust
  introuvable
  intrinsical
  in_turn