consternation (n.)

"astonishment combined with terror," 1610s, from French consternation "dismay, confusion," from Latin consternationem (nominative consternatio) "confusion, dismay," noun of state from past-participle stem of consternare "overcome, confuse, dismay, perplex, terrify, alarm," which is probably related to consternere "throw down, prostrate," from assimilated form of com-, here probably an intensive prefix (see com-), + sternere "to spread out, lay down, stretch out," from nasalized form of PIE root *stere- "to spread."