noun

• (uncountable) Modern or contemporary ideas, thought, practices, etc.
• (countable) Anything that is characteristic of modernity.
• Any of several styles of art, architecture, literature, philosophy, etc., that flourished in the 20th century.
• A religious movement in the early 20th century, condemned as heretical by Pope Pius X, which tried to reconcile Roman Catholic dogma with modern science and philosophy.