Definition of oculus in English:

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Pronunciation: /ˈäkyələs/

noun (plural oculi /-ˌlī/ /-ˌlē/)

1A round or eyelike opening or design, in particular.
Example sentences
  • Either way, feeding a signal from a microphone placed in the oculus gives a real audio picture of the size of the space.
  • What could have swayed Capponi away from the plan for an oculus and toward the tall, narrow shape employed by Marcillat?
  • Vents in the facade, the cupolas, and the oculi inside allowed air to circulate throughout the building.
1.1A circular window.
Example sentences
  • The oculus windows depicted in each of their two cells illuminate the figures with an otherworldly silvery light.
  • The sun streams in through the open oculus, tracing a circular disk across the walls and floor, creating a walk-in solar observatory.
  • The oculus window will complement two large stained glass windows that have been installed in the third-floor ceiling.
1.2The central boss of a volute.
Example sentences
  • Formed by the intersection of toroidal geometries, the roof is composed of two shells that interlock at the centre of which is a great glass oculus.
1.3An opening at the apex of a dome.
Example sentences
  • At the top of the columns a concrete-on-steel deck platform forms the oculus of the interior dome.
  • Supported by slender steel columns that splay arboreally at their tops, the concrete canopy is perforated by a series of different-sized oculi.
  • The major interior space, the Potomac rotunda, balloons under a domed ceiling with an oculus, reaching a height of 120 feet.


Mid 19th century: from Latin, literally 'eye'.

For editors and proofreaders

Syllabification: oc·u·lus

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