long-day

adjective

ˈlȯŋ-ˈdā How to pronounce long-day (audio)
: responding to or relating to a long photoperiod
—used especially of a plant compare day-neutral, short-day

Word History

First Known Use

1920, in the meaning defined above

Time Traveler
The first known use of long-day was in 1920

Rhymes for long-day

See All Rhymes for long-day

Browse Nearby Words

long dance
long-day
long-distance
See all Nearby Words

Cite this Entry

“Long-day.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/long-day. Accessed 19 Jul. 2025.

Copy Citation

Share

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

'Affect' vs. 'Effect'

More Words You Always Have to Look Up

Using Bullet Points ( • )

Why is '-ed' sometimes pronounced at the end of a word?

Words You Always Have to Look Up
See More

Popular in Wordplay

See More

Ten Painless Ways to Improve Your Vocabulary

How 'Namaste' Entered The English Language

Our Best Historical Slang Terms

'Za' and 9 Other Words to Help You Win at SCRABBLE

12 Words Whose History Will Surprise You
See More

Popular

See More

'Affect' vs. 'Effect'

Ten Painless Ways to Improve Your Vocabulary

How 'Namaste' Entered The English Language
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
a plate of arepas
Name That Dish! Some mouth-watering food for thought
See All