mega-
variant of megalo- (megalith ); also the initial element in units of measure that are equal to one million of the units denoted by the base word (megahertz ). M
mega-
American
especially before a vowel,
meg-.
mega
1
British
/ ˈmɛɡə /
adjective
mega-
2
British
combining form
-
M. denoting 10 6
megawatt
-
(in computer technology) denoting 2 20 (1 048 576)
megabyte
-
large or great
megalith
-
informal great in importance or amount
megastar
mega–
Scientific
-
A prefix that means:
-
Large, as in megadose, a large dose.
-
One million, as in megahertz, one million hertz.
-
2 20 (that is, 1,048,576), which is the power of 2 closest to a million, as in megabyte.
Usage
What does mega- mean? Mega- is a combining form used like a prefix meaning “large, great, grand, abnormally large.” It is used in many scientific and medical terms. In science, mega- is specifically used as a prefix in units of measure equaling a factor of “one million.” It’s abbreviation is M. So, a megawatt (MW) is one million watts. Mega- comes from the Greek mégas, meaning “large” or “great.”What are variants of mega-?When combined with words or word elements that begin with a vowel, mega- becomes meg-, as in megohm. Mega- is a variant of megalo- and megal-, as in megalomania and megalopsia. Learn more about their specific applications in our Words That Use articles.
Etymology
Origin of mega-
Combining form representing Greek mégas large, great
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.
See Examples For:
Beek looked at the yachts around us, mega- and not.
From Los Angeles Times ● May 9, 2023
The West is in a drought so huge that everyone started throwing the prefix mega- in front of it.
From Salon ● Dec. 29, 2021
In fact, the foundation drew contributions from some who were once Clinton’s most bitter GOP enemies, including Newsmax chief executive Christopher Ruddy and conservative mega- donor Richard Mellon Scaife.
From Washington Post ● Jun. 2, 2015
As high-flying technology stocks crashed and the mega- mergers of the late 1990s faded away, Goldman Sachs’s investment-banking revenue plunged to $2.71 billion in 2003 from $5.37 billion in 2000.
From BusinessWeek ● Jul. 22, 2011
Four of the men were shouting something through mega- phones.
From "Kaffir Boy: An Autobiography" by Mark Mathabane
Recent mega transactions, such as Whitecap Resources’ $10.44 billion combination with Veren in the Montney and Duvernay regions reflect an industry-wide push toward operational scale and infrastructure security.
From The Wall Street Journal ● Sep. 8, 2026
It went from the loft to the club to the mega bar, and now it has gone to the arena.
From Salon ● Sep. 6, 2026
Skiba pointed to AI companies tapping other sources of capital, including off-balance-sheet deals, mega financing of specific data-center projects and exotic chip-backed deals in the works.
From MarketWatch ● Aug. 19, 2026
While the couple signed a mega deal with Netflix in 2020 reportedly worth an unconfirmed $100 million, many of their projects have struggled to win over audiences.
From Barron's ● Aug. 19, 2026
“Like, I’m pretty sure NYU is mega gay.”
From "Leah on the Offbeat" by Becky Albertalli
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
