Greek for "quietness". It has given its name to the Hesychast (sometimes misspelled Hesychist) contemplative movement in Orthodox Christianity, which arose in the 14th century on Mount Athos.

Hesychasm emphasizes union with God through a process of quietism, self-purification and awareness of divine grace. Hesychast monks practice meditation on the name of Jesus and the Jesus Prayer, with the aim of achieving the state of hesychia, together with amerimnia and nepsis.

The Philokalia is one of the principal religious works of the Hesychast movement.