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Showing results for underground. Search instead for undergrou.
Definitions

underground

[uhn-der-ground, uhn-der-ground] / ˈʌn dərˈgraʊnd, ˈʌn dərˌgraʊnd /
ADJECTIVE
below the surface
Synonyms
STRONGEST
buried covered subterranean
WEAK
below ground in the recesses subterrestrial sunken underfoot
Antonyms
WEAK
aboveground authorized condoned ground known legal public sky
ADJECTIVE
secret, subversive
Synonyms
STRONGEST
clandestine experimental hidden private
STRONG
alternative avant-garde covert radical revolutionary
WEAK
concealed hush-hush on the Q.T. on the sly resistant resistive surreptitious unbowed unconventional under wraps undercover unusual
Antonyms
STRONGEST
open
STRONG
conservative
WEAK
aboveground authorized condoned ground known legal public sky

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

All members of the Satyrex genus are fossorial, meaning they spend their lives underground.

From Science Daily • Apr. 6, 2026

Then it would need to be mechanically excavated from deep underground in the middle of hostile territory and could weigh 1,000 pounds.

From Salon • Apr. 3, 2026

Another location for oil exports, Qeshm hosts a naval station and missiles in underground tunnels.

From The Wall Street Journal • Apr. 2, 2026

By the end of the pilot, we reveal they are underground.

From Los Angeles Times • Mar. 30, 2026

They also maintained the underground route through which downed Allied plane crews reached the North Sea coast.

From "The Hiding Place" by Corrie ten Boom

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.