Late Middle English (in an earlier sense). From post-classical Latin monoculus the caecum, a one-eyed person or creature, irregularly from ancient Greek μονο- + classical Latin oculus.
Definition of monoculus in US English:
monoculus
noun
Medicine. A bandage for one eye. Now rare.
Origin
Late Middle English (in an earlier sense). From post-classical Latin monoculus the caecum, a one-eyed person or creature, irregularly from ancient Greek μονο- + classical Latin oculus.