新月（しんげつ、shingetsu）
- new moon

The Japanese word 新月 （しんげつ, *shingetsu*） refers to the new moon phase. This is the phase of the lunar cycle when the moon is between the Earth and the sun, and therefore, the side of the moon facing us is not illuminated. Essentially, it's the time when the moon is invisible in the night sky. The word directly translates to "new moon."

⚫︎ 新月の夜は、星がよく見える。 Translation: Stars are easily visible on a new moon night. ⚫︎ 来週は新月なので、天体観測に最適です。 Translation: Since it's a new moon next week, it's perfect for astronomical observation. ⚫︎ 新月の日は、潮の干満差が大きくなることがある。 Translation: The difference between high and low tides can be significant on a new moon day.

You can use 新月 （しんげつ） in conversations about astronomy, the lunar cycle, or events affected by the moon's phases. It's often used in discussions about stargazing or other activities that are better during the absence of moonlight.

新月 is written with the kanji 新（*shin*）, meaning "new," and 月（*getsu* or *tsuki*）, meaning "moon." The reading is しんげつ in hiragana. There are no other common ways to write this word or variations in the okurigana. The reading しんづき also exists but is not common.

There aren't many direct synonyms for 新月 that are commonly used. You might describe the period as the time "when there is no moon" or "moonless night," but there is no simple synonymous word.

The antonym of 新月 is 満月 (*mangetsu*), which means "full moon."

今週は新月なので、キャンプに行こう！ ・Translation: Since it’s a new moon this week, let's go camping! ・Explanation: This sentence suggests planning a camping trip because the absence of moonlight will make stargazing more enjoyable.

新月の日は、夜空がとても暗く見える。 ・Translation: On a new moon day, the night sky looks very dark. ・Explanation: This highlights the darkness associated with the new moon, making it ideal for observing faint celestial objects.

The word 新月 is a compound word formed by combining the kanji 新 (shin/arata - new) and the kanji 月 (getsu/tsuki - moon). This straightforwardly describes the new phase of the moon.