in advance

Từ điển WordNet v3.1 - WordNet Dictionary

I - adjective

situated ahead or going before (Freq. 2)
- an advance party
- at that time the most advanced outpost was still east of the Rockies
• Syn:
advance, advanced
• Similar to:
front
• Derivationally related forms:
advance (for: advance)

II - adverb

ahead of time;
in anticipation (Freq. 3)
- when you pay ahead (or in advance) you receive a discount
- We like to plan ahead
- should have made reservations beforehand
• Syn:
ahead, beforehand