new moon

noun

1

: the moon's phase when it is in conjunction with the sun so that its dark side is toward the earth

also : the thin crescent moon seen shortly after sunset for a few days after the actual occurrence of the new moon phase

2

: the beginning of each Jewish month marked by a special liturgy

Examples of new moon in a Sentence

Recent Examples on the Web

On the Gregorian calendar, Lunar New Year – which lasts from the first new moon to the next full moon – generally falls in late January or early February. —Saman Shafiq, USA Today, 2 Jan. 2026

Around August 12-13, the Perseid meteor shower is expected to peak, and conditions should be ideal for viewing, with dark skies thanks to a new moon, according to EarthSky. —Lily Hautau, CNN Money, 1 Jan. 2026

Scientists discovered 128 new moons orbiting Saturn, bringing the planet’s total to 274. —Devika Rao, TheWeek, 31 Dec. 2025

In some Asian cultures, such as Chinese, Korean and Vietnamese, people celebrate the Lunar New Year between late January and February to coincide with the first new moon on the lunar calendar. —Ayana Archie, NPR, 29 Dec. 2025

Word History

First Known Use

before the 12th century, in the meaning defined at sense 1

Rhymes for new moon

• attune
• baboon
• balloon
• bassoon
• buffoon
• cartoon
• cocoon
• festoon
• gaboon
• harpoon
• immune
• impugn

Kids Definition

new moon

noun

: the moon's phase when its dark side is toward the earth

also : the thin curved outline of the moon seen shortly after sunset for a few days after the actual occurrence of the new moon phase