presidency (n.)youdaoicibaDictYouDict[presidency 词源字典]
1590s, "office of a president," from Medieval Latin praesidentia "office of a president" (mid-13c.), from Latin praesidentem (nominative praesidens) "president, governor" (see president). Earlier in same sense was presidentship (1520s). Meaning "a president's term in office" is from 1610s.[presidency etymology, presidency origin, 英语词源]