first quarter

American

noun

Astronomy.

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

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of first quarter

First recorded in 1905–10

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

One of the most exciting plays happened in the first quarter when Marcus Smart dived for a loose ball and, while prone on his back, passed to James.

From Los Angeles Times

The group had been raising their production quotas for most of last year, but paused those increases for the first quarter of 2026 on the heels of expectations for a global oil supply surplus.

From MarketWatch

Inflation is looking like it’s heating up in the first quarter, agreed Scott Anderson, chief U.S. economist at BMO Capital Markets.

From MarketWatch

Inflation is looking like it is heating up in the first quarter, agreed Scott Anderson, chief U.S. economist at BMO Capital Markets.

From MarketWatch

The Dolphins stretched the lead to 25-8 by the end of the first quarter and the margin was 19 by halftime.

From Los Angeles Times

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023