oculus.

A circular opening in a wall, roof or dome.

Use it for

Words that belong together

• roof oculus
• central oculus

On the page

Daylight entered through the central oculus and moved across the floor.

The roof oculus remained open while the smaller windows were shuttered.

Usage notes

Primary category: architecture / spatial description. Forms: Singular oculus; plural oculi. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Writing functions: precise built-space description, structural component naming, spatial orientation, interior material description. Disciplines: fiction writing, architectural description, advanced descriptive English. Commonness: uncommon.