Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

See What's Trending Now See More Trending Words

isomer

noun iso·mer \ ˈī-sə-mər \

Definition of isomer

1 :one of two or more compounds, radicals, or ions that contain the same number of atoms of the same elements but differ in structural arrangement and properties
2 :a nuclide isomeric with one or more others

See isomer defined for kids

From the M-W Editors

alt-59e77dc36c593
The Origins of 'Lobbyist'
tycoon
17 English Words that Come From Japanese
one-green-toy-robot-amidst-many-red-toy-robots
The Exceptions Quiz III
video-title-words-of-the-year-1066
Words of the Year: 1066

Recent Examples of isomer from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'isomer.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of isomer

International Scientific Vocabulary, back-formation from isomeric

Medical Dictionary

isomer

noun iso·mer \ ˈī-sə-mər \

medical Definition of isomer

1 :any of two or more compounds, radicals, or ions that contain the same number of atoms of the same elements but differ in structural arrangement and properties
2 :a nuclide isomeric with one or more others

Learn More about isomer

  1. Britannica.com: Encyclopedia article about isomer

Seen and Heard

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

show hide

Love words? Need even more definitions?

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

WORD OF THE DAY

malign

play

to speak evil of

Get Word of the Day daily email!

TRENDING NOW

  1. spurious of a deceitful nature or quality

  2. righteous We provide an assortment of definitions

  3. Kafkaesque 'A nightmarish quality'

  4. mike "microphone"

  5. moron “a very stupid person”

SEE ALL

BROWSE DICTIONARY

Test Your Vocabulary

The Exceptions Quiz III

  • one-green-toy-robot-amidst-many-red-toy-robots
  • Which of these words does not mean "nonsense"?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Add Diction

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!

Words at Play

alt-59e77dc36c593
The Origins of 'Lobbyist'

From the front hallways to the back rooms

alt-59e673567065d
The History of the Word 'Terrorism'

Noah Webster first entered the term in 1840

alt-59e65152518a6
'Regimen' vs. 'Regiment'

The rule of thumb for words about rules

alt-59e50f5a357b4
'Spox' May Go On The Record

From newsroom lingo to the mainstream

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

one-green-toy-robot-amidst-many-red-toy-robots
The Exceptions Quiz III

Which of these things doesn't belong?

Take the quiz
knupfer-painting-solon-before-croesus
Forms of Government Quiz

Name that government! Or something like that.

Take the quiz
Spell It
Spell It

Can you spell these 10 commonly misspelled words?

Take the quiz
Add Diction
Add Diction

Build a chain of words by adding one letter at a time.

Play the game