nounpl. oc·u·li Architecture
An eyelike opening or ornament, especially:
a. A round window.
b. A circular opening at the apex of a dome.
Origin of oculusMedieval Latin, from Latin, eye; see okw- in Indo-European roots.
in the dome of the Pantheon
- (architecture) A window or other opening that has an oval or circular shape (as of an eye).
- One can glimpse the sky through the oculus of the Pantheon in Rome.
From Latin oculus (“eye").