first quarter

American  

noun

Astronomy.

first quarters plural

1. the instant, approximately one week after a new moon, when one half of the moon's disk is illuminated by the sun.

---

first quarter British  

noun

1. one of the four principal phases of the moon, occurring between new moon and full moon, when half of the lighted surface is visible from earth Compare last quarter

---

Other Word Forms

Noun Inflected Forms

• first quarters
  plural

Etymology

Origin of first quarter

First recorded in 1905–10

Example Sentences

See Examples For:

first quarter

If the forecast is correct, GDP would fall short of the 2.1% increase in the first quarter.

From MarketWatch ● Jul. 29, 2026

The figures, released Wednesday, point to a slight pickup in the first quarter of next year to 2.7%, an outcome the ECB described as “stable.”

From The Wall Street Journal ● Jul. 29, 2026

Ionescu scored 14 points in the first quarter, propelling the visitors to a 36-30 lead.

From Los Angeles Times ● Jul. 29, 2026

Final sales rose at a modest 1.7% annual pace in the first quarter, below the 2.5% average per quarter since 2022.

From MarketWatch ● Jul. 29, 2026

I figured it served the coach right for making me sit out the first quarter.

From "Crash" by Jerry Spinelli