first 
(fûrst)
(fûrst)n.
1. The ordinal number matching the number one in a series.
2. The one coming, occurring, or ranking before or above all others.
3. The beginning; the outset: from the first; at first.
4. Music The voice or instrument highest in pitch or carrying the principal part.
5. The transmission gear or corresponding gear ratio used to produce the range of lowest drive speeds in a motor vehicle.
6. The winning position in a contest: finished the season in first.
7. Baseball
a. First base.
b. A first baseman.
adj.
1. Corresponding in order to the number one.
2. Coming before all others in order or location: the first house on your left.
3. Occurring or acting before all others in time; earliest: the first day of spring.
4. Ranking above all others, as in importance or quality; foremost: was first in the class.
5. Music Being highest in pitch or carrying the principal part: first trumpet.
6. Of, relating to, or being the transmission gear or corresponding gear ratio used to produce the range of lowest drive speeds in a motor vehicle.
7. Of, related to, or being a member of the US president's household: first daughter Sasha Obama.
adv.
Idiom: 1. Before or above all others in time, order, rank, or importance: arrived first; forgot to light the oven first.
2. For the first time.
3. Rather; preferably: would die first.
4. In the first place; to begin with; firstly.
first off/thing
From the start; immediately: Why wasn't I told first off? When I get to work, I have to call my lawyer first thing.
[Middle English, from Old English fyrst; see per1 in the Appendix of Indo-European roots.]