I am not sure if I can give a definition but I know one when I hear one. This is part of a novena I am praying during Lent.

The Litany of the Saints
For the Poor Souls
Lord, have mercy on us.
Christ, have mercy on us.
Lord, have mercy on us.
Christ, hear us.
Christ, graciously hear us.
God the Father of heaven, have mercy on us.
God the Son, Redeemer of the World, have mercy on us.
God the Holy Spirit, have mercy on us.
Holy Trinity, one God, have mercy on us.
Holy, Mary,*
Holy Mother of God,
Holy Virgin of Virgins,
St. Michael,
St. Gabriel,
St. Raphael,
All ye holy angels and archangels,
All ye holy orders of blessed spirits,
St. John the Baptist,
St. Joseph,
All ye holy Patriarchs and Prophets,
St. Peter.
*Pray for the faithful departed.
St. Paul,*
St. Andrew,
St. John,
All ye holy Apostles and Evangelists,
All ye holy Disciples of our Lord,
All ye holy Innocents,
St. Stephen,
St. Laurence,
St. Vincent,
All ye Holy Martyrs,
St. Sylvester,
St. Gregory,
St. Augustine,
All ye holy bishops and confessors,
All ye holy doctors,
St. Anthony,
St. Benedict,
St. Dominic,
St. Francis,
All ye holy priests and levites,
All ye holy monks and hermits,
St. Mary Magdalene,
St. Agatha,
St. Lucy,
St. Agnes,
St. Cecilia,
St. Anastacia,
All ye holy Virgins and Widows,
All ye holy men and women, Saints of God.
*Pray for the faithful departed.
Christ, hear us,
Christ, graciously hear us,
Lord, have mercy on us,
Christ, have mercy on us,
Lord, have mercy on us,
Pray for us, all ye saints of God.
That we may be made worthy of the promises of Christ.