underground

Adjective

Positive underground

Comparative more underground

Superlative most underground

1. of or about being under the ground

   Underground water is drying up.

2. secret or not well known

   The underground music scene is really interesting.

   Underground drug sales have increased over the last year.

Related words

• under
• ground

Preposition

Preposition underground

1. being or moving under the ground

   Let's go underground. It's safer down there.

   The new trains will run underground.

2. If you go underground, you keep your activities secret.

Noun

Singular underground

Plural undergrounds

1. The underground is a system of trains that runs mostly under the ground.

   The London underground is a great way to move about the city.

Synonyms

• subway