Backsight
Part of speech: verb
Definition: To shoot a backsight.
Part of speech: noun
Definition: The rear sight of a firearm. A measurement or reading taken back towards a point of known elevation, used to calculate the height of the theodolite. A measurement of a previously shot point, used to set the angle to zero when occupying a new position.
Foresight
Part of speech: noun
Definition: The ability to foresee or prepare wisely for the future.