Synonyms for Between:

adj.

middle (adjective)
intermediate, midway, betwixt and between.

adv.

all (adverb)
betwixt.
middle from two points (adverb)
betwixt, halfway, in, in the middle, intervening, medially, mid, midway, within, Inserted, Interpolated, bounded by, centrally located, enclosed by, in the thick of, 'tween.

n.

all, before, here, last, sometime, then, when, This, Until, Whenever. equidistant, intermediate, poised, in our/their/your midst. direct, directly, squarely, vicarious, First-hand, Participative, close to home, first/second/third hand, from the horse's mouth, through someone's eyes. between (noun)
betwixt, 'tween.

v.

separating (verb)
connecting, halfway, in, in the middle, in-between, intervening, medially, mid, midway, within, Inserted, Interjacent, Interpolated, Linking, betwixt and between, bounded by, centrally located, enclosed by, in the thick of, intermediate to, sandwichwise.

Other synonyms:

equidistant, halfway, in-between, intervening, mid, midway. poised. Other relevant words:
betwixt, direct, equidistant, halfway, in, in the middle, in-between, intermediate, intervening, medially, mid, midway, when, within, Inserted, Interpolated, betwixt and between, bounded by, centrally located, enclosed by, in the thick of.

Usage examples for between

  1. So it's a secret- just between you and me, Polycarp Jenks! – Lonesome Land by B. M. Bower
  2. It must be a secret between us. – Star-Dust A Story of an American Girl by Fannie Hurst
  3. But there was something between these two, Maggie and Aunt Anne. – The Captives by Hugh Walpole