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
Words nearby mega-
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. 2020
British Dictionary definitions for mega-
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
Medical definitions for mega-
One million (106):megahertz.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Scientific definitions for 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.