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.
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.
Origin
Middle English (denoting a runner or running messenger): from Latin,‘runner,’ from curs-. The sense ‘sliding part of an instrument’ dates from the late 16th cent.