1. earlier in time than; prior to
2. in front of; ahead of in position or order

1. at an earlier time; previously

1. earlier than the time when; prior to the time that

Examples

• I need to finish my homework before dinner.
• She arrived before me at the meeting.
• The car stopped before the red light.
• Have you been here before?
• Call me before you leave the house.
• The letter B comes before C in the alphabet.
• I had never seen such a beautiful sunset before.