Catechism of the Catholic Church §633 — excerpt
Scripture calls the abode of the dead, to which the dead Christ went down, "hell" - Sheol in Hebrew or Hades in Greek - because those who are there are deprived of the vision of God.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: Roman Catechism 1, 6, 3 · Council of Rome (745): DS 587 · Benedict XII, Cum dudum (1341): DS 1011 · Clement VI, Super quibusdam (1351): DS 1077 · Council of Toledo IV (625): DS 485