rest mass

noun

Definition of rest mass

: the mass of a body exclusive of additional mass the body acquires by its motion according to the theory of relativity

First Known Use of rest mass

1914, in the meaning defined above

Keep scrolling for more

Learn More about rest mass

Statistics for rest mass

Look-up Popularity

Time Traveler for rest mass

The first known use of rest mass was in 1914

See more words from the same year

More from Merriam-Webster on rest mass

Rhyming Dictionary: Words that rhyme with rest mass

Britannica.com: Encyclopedia article about rest mass

Comments on rest mass

What made you want to look up rest mass? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to move or obtain by small maneuvers

Get Word of the Day daily email!

Test Your Vocabulary

Summer 2019 Words of the Day Quiz

  • a-bowl-of-peach-sorbet-with-cut-peaches-next-to-it
  • Which is a synonym of desideratum?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!