Between (preposition)

1. In the space separating (two things).
2. In or into the time separating (two periods).
3. In or into the interval separating (two points).
4. Shared by (two or more people or things).
5. In the position or relationship of a middle point.

Origin:

Old english betweonum, from be- "by" + tweonum "two".

Examples:

1. He is sitting between them.
2. I will put it between the books.
3. She is living between two worlds.
4. The war was fought between the countries.
5. We are stuck between a rock and a hard place.