I. preposition
Etymology: Middle English betwene, preposition & adverb , from Old English betwēonum, from be- + -twēonum (dative plural) (akin to Gothic tweihnai two each); akin to Old English twā two Date: before 12th century
1. by the common action of ; jointly engaging , in common to ; shared by ,
2. in the time, space, or interval that separates, in intermediate relation to,
3. from one to another of , serving to connect or unite in a relationship (as difference, likeness, or proportion) , setting apart ,
4. in preference for one or the other of , in point of comparison of , in confidence restricted to , taking together the combined effect of ,
Usage: There is a persistent but unfounded notion that between can be used only of two items and that among must be used for more than two. Between has been used of more than two since Old English; it is especially appropriate to denote a one-to-one relationship, regardless of the number of items. It can be used when the number is unspecified
II. adverb Date: before 12th century in an intermediate space or interval