Four (numeral)

1. The cardinal number equal to the sum of 3 and 1.
2. The fourth in a set or series.
3. A group or set of four things.

Origin:

From middle english four, fower, feower, from old english fēower, from proto-germanic *fedwōr, from proto-indo-european *kʷetwóres. .

Examples:

1. I need four more chairs for the dinner party.
2. This is the fourth time I've read this book.
3. The four of us decided to split the cost of the hotel room.
4. There are four seasons in a year.
5. A square is a shape with four sides of equal length.