crosshair

/ˈkrɔsˌhɛr/
noun
  1. A thin line or wire in the center of a gun sight or optical instrument (like a telescope or microscope) used to aim or measure.
    • The sniper adjusted the crosshair on his rifle scope before taking the shot.
    • The crosshair in the telescope helped the astronomer locate the distant star.
    • She aligned the crosshair of the microscope with the center of the cell.
Synonyms
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