Did you know?

Click any word in a definition or example to find the entry for that word

Jekyll and Hyde - definition and synonyms

What are red words?

90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.

Thesaurus diagram

The thesaurus of synonyms and related words is fully integrated into the dictionary. Click on the thesaurus category heading under the button in an entry to see the synonyms and related words for that meaning.

noun [singular]     Jekyll and Hyde pronunciation in American English
/ˌdʒek(ə)l ən ˈhaɪd/
  1. someone who seems to have two different personalities, one good and one bad
Word story
From the name of a character who appears in the book The Strange Case of Dr. Jekyll and Mr. Hyde by the British writer Robert Louis Stevenson.

deep learning

a form of machine learning which incorporates the use of neural networks

BuzzWord Article

Open Dictionary

snap election

a general election … that is called earlier than expected

add a word


A must for anyone with an interest in the changing face of language. The Macmillan Dictionary blog explores English as it is spoken around the world today.

global English and language change from our blog
Macmillan learn live love play