English · Word Candidate

underground

/ˌʌn.dəˈɡɹaʊnd/

Proposed by a contributor, not yet supported by evidence.

Also seen as: undergrounds · undergrounding · undergrounded

Sense 1

Both English Tiếng Việt

Meaning · English

Below the ground; below the surface of the Earth.

Nghĩa · Tiếng Việt

Dưới mặt đất

Machine-translated — suggest a fix

Adjective

Examples

There is an underground tunnel that takes you across the river.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 2

Both English Tiếng Việt

Meaning · English

Hidden, furtive, secretive.

Nghĩa · Tiếng Việt

Ẩn, bí mật, kín đáo

Machine-translated — suggest a fix

Adjective

Examples

These criminals operate through an underground network.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 3

Both English Tiếng Việt

Meaning · English

Below the ground.

Nghĩa · Tiếng Việt

Dưới mặt đất

Machine-translated — suggest a fix

Adverb

Examples

The tunnel goes underground at this point.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 4

Both English Tiếng Việt

Meaning · English

Secretly.

Nghĩa · Tiếng Việt

Bằng cách bí mật

Machine-translated — suggest a fix

Adverb

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Common questions

What does “underground” mean?

Below the ground; below the surface of the Earth.

Is “underground” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.