open sight
noun
(on a firearm) a rear sight consisting of a notch across which the gunner aligns the front sight on the target.
Compare
peep sight.
Origin of open sight
First recorded in 1585–95
Words nearby open sight
open sentence,
open sesame,
open set,
open shop,
open side,
open sight,
open slather,
open source,
open space,
open stance,
open stock