n the first or highest in an ordering or series
n the first element in a countable series
n the time at which something is supposed to begin
n the fielding position of the player on a baseball team who is stationed at first of the bases in the infield (counting counterclockwise from home plate)
n an honours degree of the highest class
n the lowest forward gear ratio in the gear box of a motor vehicle; used to start a car moving
n. 一等品；一级品（first的复数形式）