Un"der*world` (?), n. 1. The lower of inferior world; the world which is under the heavens; the earth.

That overspreads (with such a reverence)
This underworld.

2. The mythological place of departed souls; Hades.

3. The portion of the world which is below the horizon; the opposite side of the world; the antipodes. [R.]

Fresh as the first beam glittering on a sail,
That brings our friends up from the underworld.

4. The inferior part of mankind. [R.] Atterbury.

Un"der*world` (?), n. 1. The lower of inferior world; the world which is under the heavens; the earth.

That overspreads (with such a reverence)
This underworld.

2. The mythological place of departed souls; Hades.

3. The portion of the world which is below the horizon; the opposite side of the world; the antipodes. [R.]

Fresh as the first beam glittering on a sail,
That brings our friends up from the underworld.

4. The inferior part of mankind. [R.] Atterbury.

• That part of society that is engaged in crime or vice.
  
• (mythology) The world of the dead, located underneath the world of the living; the afterlife.