Ressie is a variant of the name Theresa. Theresa originates in Greek language and means "summer harvest". It is a variant of the name Teresa, used in Spanish and Portuguese. There have been several Roman Catholic saints of this name until now, most recently Blessed Mother Teresa of Calcutta, a nun who founded the Missionaries of Charity in Calcutta in 1950, and for over 45 years helped the sick and poor in India.