adjacence (n.)

c. 1600, from Medieval Latin adjacentia, abstract noun from Latin adiacens "lying at," present participle of adiacere "lie at, border upon, lie near," from ad "to" (see ad-) + iacēre "to lie, rest," related to iacere "to throw; lay ('cast (oneself) down')," from PIE root *ye- "to throw, impel."