from “Online Etymology Dictionary”

ecstasy (n.) late 14c., extasie “elation,” from Old French estaise “ecstasy, rapture,” from Late Latin extasis, from Greek ekstasis “entrancement, astonishment, insanity; any displacement or removal from the proper place,” in New Testament “a trance,” from existanai “displace, put out of place,” also “drive out of one’s mind” (existanai phrenon), from ek “out” (see ex-) + histanai “to place, cause to stand,” from PIE root *stā- “to stand” (see stet).