Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “ED”


noun [U] uk   /ˌiː ˈdiː/ us    // specialized
abbreviation for erectile dysfunctionDiseases of the reproductive system
abbreviation for effective dose: the amount of a drug that produces the effect that is wantedAdministering drugs and medicines
(Definition of ED noun from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of ED?
Add Cambridge dictionaries to your browser to your website

Definitions of “ED” in other dictionaries

Word of the Day


a measure for liquid equal to about half a litre

Word of the Day


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