Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “mortal sin”

mortal sin

noun [C usually singular]    
in the Roman Catholic religion, an action that is so bad that you will be punished for ever after your death if you do not ask God to forgive youSin
(Definition of mortal sin noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of mortal sin

Translations of “mortal sin”

Word of the Day

closeness

the quality of knowing someone very well, liking them a lot, and wanting to spend a lot of time together

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