Dictionary.com

MW

Save This Word!

Electricity. megawatt; megawatts.

QUIZZES

QUIZ YOURSELF ON “ITS” VS. “IT’S”!

Apostrophes can be tricky; prove you know the difference between it’s and its in this crafty quiz!
Question 1 of 12
On the farm, the feed for chicks is significantly different from the roosters’; ______ not even comparable.

Definition for MW (2 of 2)

mW

Electricity.

milliwatt; milliwatts.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

VOCAB BUILDER

What does MW mean?

In the context of dictionaries, MW stands for “many words.” Or something like that. If you’re here because you searched for “MW dictionary,” well, you’ve come to the right place as far as we’re concerned, because, oh yes, we’ve got many words.

MW is really an abbreviation, though, and it can stand for a lot of different things.

Most commonly, MW stands for megawatt, a unit of power equal to one million watts.

Sometimes, the two letters are used as an abbreviation for milliwatt, a unit equal to one thousandth of a watt. In this case, it is typically styled as mW. 

In other scientific contexts, MW is an abbreviation for molecular weight—the sum of the atomic weights of all the atoms in a molecule.

In URLs, .mw is the internet domain for Malawi.

MW can also stand for medium wave (a type of radio wave) or Master of Wine, a certification issued to wine experts.

And, OK, yes, when you see MW or M-W in the context of dictionaries, it often refers to the George and Charles Merriam/Noah Webster mashup. You know, “since 1828” and all that. (See you at the convention, M Dub!)

Example: The station is capable of generating 1,000 MW of power.

Where does MW come from?

The abbreviation MW has been used for megawatt since at least the late 1940s. The term megawatt was first recorded around 1895. The prefix mega- comes from a word meaning “large.” It’s used in units of measure that are equal to one million of the units denoted by the base word: a megawatt is equal to one million watts. A gigawatt is equal to one billion watts. It should not be confused with the (not actually real) jiggawatt, which, if we had to guess, is probably equal to one jillion watts. The word watt comes from the name of scientist James Watt and was first recorded in 1882.

Megawatt is sometimes used in figurative ways, such as to describe things as exceptionally bright or powerful, as in She had a 10,000-megawatt smile or Dictionary.com is like a 10 billion-MW dictionary.

Did you know ... ?

What are some words that share a root or word element with MW

 

What are some words that often get used in discussing MW?

 

How is MW used in real life?

MW is most commonly used as an abbreviation for megawatt.

 

Try using MW!

Which of the following terms can be abbreviated as MW?

A. molecular weight
B. megawatt
C. Malawi
D. all of the above

British Dictionary definitions for MW (1 of 2)

mw

the internet domain name for

Malawi

British Dictionary definitions for MW (2 of 2)

MW

symbol for

megawatt

abbreviation for

radio medium wave
Master of Wine
Malawi (international car registration)
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 MW

MW

abbr.

molecular weight
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Get Online Help For Kids!