Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “big bang theory”

big bang theory

noun [U]  /ˈbɪɡ ˈbæŋ ˌθɪər·i/
the very large explosion of a single mass of matter that many scientists believe was the beginning of the universe
(Definition of big bang theory noun from the Cambridge Academic Content Dictionary © Cambridge University Press)

Word of the Day

workmanship

the skill with which something was made or done

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More