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

Supermoons happen when a new moon or a full moon is at its closest to Earth all month, according to NASA. —Julia Gomez, USA Today, 3 Nov. 2025

The best time to shoot constellations is during a new moon because of the dark skies that allow fainter stars to shine in the night sky. —Harry Bennett, Space.com, 30 Oct. 2025

The best conditions are during a new moon or when the moon is below the horizon during peak viewing hours. —Hannah Parry, MSNBC Newsweek, 21 Oct. 2025

When, where to watch shooting stars in California sky The Orionids will be at their best at the same time of the October new moon. —Hannah Poukish, Sacbee.com, 21 Oct. 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