between

American Heritage® Dictionary of the English Language, Fourth Edition

1. prep. In or through the position or interval separating: between the trees; between 11 o'clock and 12 o'clock.
2. prep. Intermediate to, as in quantity, amount, or degree: It costs between 15 and 20 dollars.
3. prep. Usage Problem Connecting spatially: a railroad between the two cities.
4. prep. Usage Problem Associating or uniting in a reciprocal action or relationship: an agreement between workers and management; a certain resemblance between the two stories.
5. prep. In confidence restricted to: Between you and me, he is not qualified.
6. prep. By the combined effort or effect of: Between them they succeeded.
7. prep. In the combined ownership of: They had only a few dollars between them.
8. prep. As measured against. Often used to express a reciprocal relationship: choose between riding and walking.
9. adv. In an intermediate space, position, or time; in the interim.
10. idiom. in between In an intermediate situation: My roommates disagreed and I was caught in between.
11. idiom. in between times During an intervening period; in the meantime: has written several books and teaches in between times.

Century Dictionary and Cyclopedia

1. In the space which separates (two points, places, objects, or lines); at any point of the distance from one to the other of: as, between the eyes; between Washington and Philadelphia; the prisoner was placed between two policemen.
2. In intermediate relation to, as regards time, quantity, or degree: as, it occurred between his incoming and outgoing; a baronet is between a knight and a baron; they cost between $5 and $6 each; between 12 and 1 o'clock.
3. In the mutual relations of: as, discord exists between the two families.
4. From one to another of, as in the exchange of actions or intercourse.
5. In the joint interest or possession of: as, they own the property between them.
6. By the action, power, or effort of one or both of.
7. In regard to the respective natures or qualities of: as, to distinguish between right and wrong.
8. In regard to one or the other of: as, to choose between two things.
9. In the intermediate space; in intermediate relation as regards time, etc.: with an object understood.
10. n. One of a grade of needles between sharps and blunts.

Wiktionary

1. prep. In the position or interval that separates (two things), or intermediate in quantity or degree. (See the Usage notes below.)
2. prep. Done together or reciprocally.
3. prep. Shared in confidence.
4. prep. In transit from (one to the other, or connecting places).
5. prep. Combined (by effort or ownership).
6. prep. One of (representing a choice).

GNU Webster's 1913

1. prep. In the space which separates; betwixt.
2. prep. Used in expressing motion from one body or place to another; from one to another of two.
3. prep. Belonging in common to two; shared by both.
4. prep. Belonging to, or participated in by, two, and involving reciprocal action or affecting their mutual relation.
5. prep. With relation to two, as involved in an act or attribute of which another is the agent or subject.
6. prep. In intermediate relation to, in respect to time, quantity, or degree.
7. n. Poetic & R. Intermediate time or space; interval.

WordNet 3.0

1. adv. in between
2. adv. in the interval