mo·noc·u·lar I. \məˈnäkyələ(r)\adjective Etymology: Late Latin monoculus having one eye + English -ar — more at monocle 1.: of, involving, or affecting a single eye < a monocular cataract > 2.: relating or adapted to the use of only one eye < monocular vision > < a monocular microscope > • mo·noc·u·lar·lyadverb II. noun : a monocular device (as a microscope or a field glass)