The Collaborative International Dictionary of English v.0.48:

Monocular \Mo*noc"u*lar\, a. [L. monoculus; Gr. mo`nos single +
   L. oculus eye: cf. F. monoculaire.]
   1. Having only one eye; with one eye only; as, monocular
      vision.
      [1913 Webster]

   2. Adapted to be used with only one eye at a time; as, a
      monocular microscope.
      [1913 Webster]