- Also called cross wire. one of the fine wires or fibers, strands of spider web, or the like, crossing in a focal plane of an optical instrument to center a target or object or to define a line of sight.
- one of the marks that aid in the positioning of overlaying images for correct registration in printing.Compare register(def 11b).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for cross hair
The "radius of measurement" is the distance between the front face of the revolving mirror and the cross-hair of the micrometer.
Then the screw was turned till the cross-hair bisected the deflected image of the slit.
After the cross-hair indicators and the level have been attached to the camera, adjustments are necessary.The Boy Mechanic, Book 2