Lewis & Short

inter-fundo, fūdi, fūsum, 3, v. a. [2. fundo], to pour between; pass., to flow between (mostly poet.): pelagus interfunditur oras, Avien. Perieg. 250.
Hence, in-terfūsus, a, um, Part.: interfusum mare, Plin. 3, 8, 14, § 86: Dido maculis trementis interfusa genas, stained with spots (of blood), Verg. A. 4, 644: Styx coërcet (animas), interposed, id. ib. 6, 439: interfusa nitentes Vites aequora Cycladas, Hor. C. 1, 14, 19: oceanus, Plin. 2, 68, 68, § 173: nox, intervening, Stat. Th. 3, 677: opacitas, intervening, Plin. 6, 23, 25, § 93.