M-day

noun

ˈem-ˌdā How to pronounce M-day (audio)
: a day on which a military mobilization is to begin

Word History

Etymology

mobilization day

First Known Use

1924, in the meaning defined above

Time Traveler
The first known use of M-day was in 1924

Dictionary Entries Near M-day

MD

M-day

MDC

See More Nearby Entries 

Cite this Entry

“M-day.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/M-day. Accessed 22 Nov. 2024.

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 All

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

Plural and Possessive Names: A Guide

The Difference Between 'i.e.' and 'e.g.'

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

What's the difference between 'fascism' and 'socialism'?
See All

Popular in Wordplay

See All

8 Words with Fascinating Histories

8 Words for Lesser-Known Musical Instruments

Birds Say the Darndest Things

10 Words from Taylor Swift Songs (Merriam's Version)

10 Scrabble Words Without Any Vowels
See All

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 Word Game 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
little chihuahua dressing like a turkey for thanksgiving
Giving Thanks Quiz Decide which words express gratitude and which gi...