Moon Phase Names & What They Mean
Every moon phase has a name that describes exactly what you see — once you know the two key words, the whole vocabulary clicks into place. The live moon above shows which phase we are in at this moment.
The two words that unlock every name
Waxing means the lit part is growing; waning means it is shrinking. Crescent means less than half is lit; gibbous means more than half. Combine them — "waxing gibbous" = growing and more than half lit — and every name becomes self-explanatory.
The four primary phases
New Moon (not visible), First Quarter (right half lit), Full Moon (fully lit), and Last Quarter (left half lit). These are precise astronomical moments, evenly spaced about a week apart.
The four intermediate phases
Between the primaries sit Waxing Crescent, Waxing Gibbous, Waning Gibbous, and Waning Crescent. These are spans of time rather than single instants — the Moon spends several days in each.
Why "quarter" when half is lit?
First and Last Quarter refer to the Moon being one quarter and three quarters of the way through its cycle. The name marks progress around the orbit, not the fraction of light you see.
Frequently Asked
What are the names of the moon phases?
New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent.
What does gibbous mean?
Gibbous describes a moon that is more than half but not fully lit — the shape between a quarter moon and a full moon.
What does waxing and waning mean?
Waxing means the illuminated portion is increasing toward full; waning means it is decreasing toward new.
Why is a half-lit moon called a quarter moon?
Because the Moon has travelled a quarter (or three quarters) of the way around its orbit. The label tracks the cycle, not the amount of light.