Three (numeral)

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

Origin:

From middle english three, threo, thrie, from old english þrīe, from proto-germanic *þrīz, from proto-indo-european *tréyes. .

Examples:

1. I need three apples for this recipe.
2. This is the third time I've had to remind you.
3. The three of us went on a road trip together.
4. There are three main components to this machine.
5. The triangle is a shape with three sides.