1) Professionally means the joint between two pipes (as in plumming)
2) Refers to a very smelly undesired (by both sex's) vagina. Probablyoriginated referring to a girls plumming.
Sally: She's got such a flange.
Kaylee: How would you know that? I thought you were straight?
Sally: I mean the pipes beind her sink.
Kaylee: Oh. Haha.