Dictionary.com

mega-

Save This Word!

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). Symbol: M
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?
Also especially before a vowel, meg-.

Origin of mega-

Combining form representing Greek mégas large, great
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use mega- in a sentence

British Dictionary definitions for mega- (1 of 2)

mega
/ (ˈmɛɡə) /

adjective
slang extremely good, great, or successful

Word Origin for mega

C20: probably independent use of mega-

British Dictionary definitions for mega- (2 of 2)

mega-

combining form
denoting 10 6megawatt Symbol: M
(in computer technology) denoting 2 20 (1 048 576)megabyte
large or greatmegalith
informal great in importance or amountmegastar

Word Origin for mega-

from Greek megas huge, powerful
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

Scientific definitions for mega-

mega-

A prefix that means:
Large, as in megadose, a large dose.
One million, as in megahertz, one million hertz.
220 (that is, 1,048,576), which is the power of 2 closest to a million, as in megabyte.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK