In computer security, an attempt to gain access to a system by posing as an authorized user. 在計算機安全學中，試圖以裝成一個合法用戶來獲取對某系統的訪問權。
A unique string of characters input by an authorized user in order to gain access to a system or to protected information in the system. Passwords are usually not displayed on terminal screen upon input, in order to preserve their secrecy. 被授權的用戶為取得對系統或系統中被保護的信息的存取權而輸入給系統的專門的字元串。為使口令字保密，輸入時口令字一般不在終端屏幕上顯示出來。
