be·fore 
(bĭ-fôr)
(bĭ-fôr)adv.
1. Earlier in time: They called me the day before.
2. In front; ahead.
prep.
1. Previous to in time; earlier than.
2. In front of.
3. In store for; awaiting: The young man's whole life lies before him.
4. Into or in the presence of: She asked that the visitor be brought before her.
5. Under the consideration or jurisdiction of: The case is now before the court.
6. In a position superior to: The prince is before his brother in the line of succession.
conj.
1. In advance of the time when: See me before you leave.
2. Rather than; sooner than: I will die before I will betray my country.
[Middle English bifore, from Old English beforan; see per1 in the Appendix of Indo-European roots.]