Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “underground”

See all translations

underground

adjective, adverb [not gradable]  /ˌʌn·dərˈɡrɑʊnd/ us  
below the surface of the earth; below ground: an underground garage Something that is done underground is secret or hidden, usually because it is not traditional or is shocking or illegal: an underground newspaper Officials believe the sighting of the suspect may have forced him to go underground (= to become secret).
(Definition of underground adjective, adverb from the Cambridge Academic Content Dictionary © Cambridge University Press)
What is the pronunciation of underground?
Add Cambridge dictionaries to your browser to your website

More American English definitions for “underground”

Definitions of “underground” in other dictionaries

Word of the Day

derivative

If something is derivative, it is not the result of new ideas, but has been developed from or copies something else.

Word of the Day

Euphemisms (Words used to Avoid Offending People)

by Kate Woodford,
March 04, 2015
​​​ We recently looked at the language that we use to describe lies and lying. One area of lying that we considered was ‘being slightly dishonest, or not speaking the complete truth’. One reason for not speaking the complete truth is to avoid saying something that might upset or offend people. Words and

Read More 

snapchat verb

March 02, 2015
to send someone a message using the photomessaging application Snapchat We used to have a thing until he got a girlfriend. now

Read More