Lewis & Short

2. interpŏsĭtus, ūs, m. (only in abl. sing.), a putting between, interposition (rare but class.): luna interpositu interjectuque terrae repente deficit, Cic. N. D. 2, 40, 103: solis radios luna interpositu suo auferens terrae, Plin. 2, 10, 7, § 47.