A crosshair is another name for a reticle. Other meanings include:

Portable data collection device with crosshair targeting illumination assembly
Reverse Engineering of DRAMs: Row Hammer with Crosshair
Axis intersection measurement of three-axis turntable with two crosshair targets
Light field and crosshair quality assurance test using a simple lens system
A method for center location of infrared crosshair
豪門盛宴——華碩M2-CROSSHAIR主板細節(jié)賞析
3D Manipulations in Handheld Augmented Reality Applications
METHOD AND APPARATUS FOR AUTOMATIC DENSITOMETER ALIGNMENT
Axis Intersection Measurement of Three-axis Turntable with a Filament
Application of Photoshop in Radiation Field Verification and Quality Assurance with Influence of Gantry Position on Accuracy of Lead...