Definition of oculus in English:



  • 1Architecture
    A round or eye-like opening or design.

    • ‘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.’
    • ‘Each of the upper study areas has an oculus in the floor revealing its counterpart below.’
    1. 1.1A circular window.
      • ‘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.’
      • ‘A large oculus brings a cylinder of light down into the main library, bathing the interior in a softly luminous glow.’
      • ‘The light entering through the oculus at the top floods the space with hypnotic patterns of light and shadow.’
    2. 1.2The central boss of a volute.
      ‘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.’
    3. 1.3An opening at the apex of a dome.
      • ‘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.’
      • ‘A round stained glass window will be installed above the oculus (opening at the top of the dome).’
      • ‘At the centre of the dome is an oculus, a circular hole, which is the only source of light.’


Mid 19th century from Latin, literally ‘eye’.