noun
equinox
EK-wih-nahks/ˈekwɪnɑːks/
Either of the two times each year when day and night are nearly equal in length worldwide.
The diagram shows the sun aligned with the equator at an equinox.
Etymology
The name means “equal night”: the night is being compared with the day. It names the time when daylight and darkness are nearly equal in length worldwide.
In context
grows longer until the vernal equinox when the length of the day equals that of the night
More examples
- The class tracks the sun's position around the equinox.
- An equinox occurs in both March and September.
- The festival is held near the autumn equinox.
Forms
equinox · equinoxes
Similar words
- solstice
- A solstice brings the year’s longest or shortest daylight; an equinox occurs when the sun crosses the equator.
- equilux
- Equilux is a day with approximately equal daylight and darkness; equinox names the sun’s crossing of the celestial equator.