Did you know?

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

Boolean - 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.

adjective computing     Boolean pronunciation in British English

Related words

  1. a Boolean search is one using the words ‘and’, ‘or’, and ‘not’ to find a word or combination of words using an Internet search engine. For example you could ask to search for ‘car or automobile’, or ‘New York and not New York state’.

Open Dictionary


a rise in the level of a stream or river

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