declension

noun declension

• decline — If something declines, it becomes less in quantity, importance, or strength.
• decay — When something such as a dead body, a dead plant, or a tooth decays, it is gradually destroyed by a natural process.
• degeneracy — If you refer to the behaviour of a group of people as degeneracy, you mean that you think it is shocking, immoral, or disgusting.
• decadence — deterioration, esp of morality or culture; decay; degeneration
• declination — the angular distance, esp in degrees, of a star, planet, etc, from the celestial equator measured north (positive) or south (negative) along the great circle passing through the celestial poles and the body