Eclipses glossary
What is an eclipse?
Eclipse is an event in which one celestial body moves into another body's shadow or blocks the observer's view of another body.
What it means
Eclipse is part of eclipse geometry and timing. Eclipses require the Sun, Earth, and Moon to align near the points where the Moon's tilted orbit crosses the ecliptic. That tilt is why an eclipse does not occur at every new or full Moon.
Sources and further reading
This definition was written in plain language and checked against these science references.