new moon

American  

noun

• new moons
  plural

1. the moon either when in conjunction with the sun or soon after, being either invisible or visible only as a slender crescent.

2. the phase of the moon at this time.

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new moon British  

noun

1. the moon when it appears as a narrow waxing crescent

2. the time at which this occurs

3. astronomy one of the four principal phases of the moon, occurring when it lies between the earth and the sun

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new moon Scientific  

/ no̅o̅ /

1. The phase of the Moon that occurs when it passes between Earth and the Sun, making it either invisible or visible only as a thin crescent at sunset.

2. See more at moon Compare full moon

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Other Word Forms

Noun Inflected Forms

• new moons
  plural

Etymology

Origin of new moon

before 1000; Middle English; Old English

Compare meaning

How does new-moon compare to similar and commonly confused words? Explore the most common comparisons:

• new moon vs. full moon

Example Sentences

See Examples For:

new moon

A new moon means moonlight should not interfere with viewing, creating favourable conditions if skies remain clear.

From BBC ● Aug. 9, 2026

With the event coinciding with a new moon for the first time since 2018, you just need to find a dark spot away from city lights and enjoy the display.

From The Wall Street Journal ● Mar. 27, 2026

This is thanks to the new moon, which cuts down on natural light — though unfortunately not L.A.’s widespread light pollution.

From Los Angeles Times ● Oct. 18, 2025

To find out, the group systematically observed the worms' daily activities when there was a new moon.

From Science Daily ● Apr. 15, 2024

Instead he feigned great interest in the . clouds and he cried, “That cloud which hangs upon the left horn of the new moon speaks of rain. It will come not later than tomorrow night.”

From "The Good Earth" by Pearl S. Buck