ETYM Latin abyssus a bottomless gulf, from Greek for bottomless; a priv. + byssos depth, bottom.
(Irregular plural: abysses).
A bottomless gulf or pit; SYN. abysm.
Any unfathomable (or apparently unfathomable) cavity or chasm or void extending below (often used figuratively)

ETYM AS. hell; akin to Dutch hel, Old High Germ. hella, German hölle, Icel. hal, Swed. helfvete, Dan. helvede, Goth. halja, and to AS. helan to conceal. Related to Hele, Conceal, Cell, Helmet, Hole, Occult.
1. A cause of difficulty and suffering; SYN. blaze.
2. Any place of pain and turmoil; SYN. hell on earth, the pits, inferno.
3. Noisy and unrestrained mischief; SYN. blaze.
In various religions, a place of posthumous punishment. In Hinduism, Buddhism, and Jainism, hell is a transitory stage in the progress of the soul, but in Christianity and Islam it is eternal (purgatory is transitory). Judaism does not postulate such punishment.
In the Bible, the word “hell” is used to translate Hebrew and Greek words all meaning “the place of departed spirits, the abode of the dead”. In medieval Christian theology, hell is the place where unrepentant sinners suffer the torments of the damned, but the 20th-century tendency has been to regard hell as a state of damnation (that is, everlasting banishment from the sight of God) rather than a place. + prikaži više

In astrophysics, a unit for describing the temperature inside a star. One inferno is 1 billion K, or approximately 1 billionşC.

ETYM New Lat., from Greek pan all + daimon a demon.
1. An utterly lawless, riotous place or assemblage.
2. The great hall or council chamber of demons or evil spirits.

Yoo-hoo, used to attract attention or as a call to persons!