Definitions
1.prepositionUp to the time of (something happening)."If you can wait until after my meeting with her, we'll talk then."
2.prepositionUp to (a certain place)"Keep walking until the second set of traffic lights, then turn left."
3.prepositionBefore (a time).
4.prepositionTo; physically towards.
5.conjunctionUp to the time that (a condition becomes true).
6.conjunctionBefore (a condition becoming true).