1) British slang for the vagina 2) Greeting spot 3) It may be for outgoing people 4) Knocking spot 5) Main entrance 6) Main entrance to a house 7) Main way in 
Front door is British slang for the vagina.
[n] - exterior door (at the entrance) at the front of a building
NATO codename for soviet missile fire control radar [SU]
front entrance noun exterior door (at the entrance) at the front of a building
the main entrance to a house or other building, usually facing a street. · anything offering the best, most direct, or most straightforward approach to a place, situation, objective, etc.