cursor
/ˈkɜːsə(r)/noun
1- a movable indicator on a computer screen identifying the point that will be affected by input from the user, for example showing where typed text will be inserted（计算机的）光标。
1.1
- chiefly historical the transparent slide engraved with a hairline that is part of a slide rule and is used for marking a point on the rule while bringing a point on the central sliding portion up to it〈主史〉（计算尺的）游标。
词源
Middle English (denoting a runner or running messenger)： from Latin, 'runner', from curs- （see CURSIVE）. The sense 'sliding part of an instrument' dates from the late 16th cent.