According to the Diccionario de la lengua española, santo has no less than 16 meanings. Among them:
- Perfect and free of sin.
- A person declared as such by the Church.
- A virtuous person.
- Said of a something that is dedicated to God or a holy service.
- Said of something that is venerated.
- Describing a religious festival.
- Sacred.
- Holy.
- Said of something that brings good luck.
- Characteristic of the Catholic church.
- A person's saint's day or name day.
- A picture of a saint.
- A type of portrait in a book.
- ¿A santo de qué?: Why in the world?
- Llegar y besar el santo: to succeed at something immediately or on the first try. (Su sustituto, Juanjo, llegó y besó el santo: gol en su primer partido. His substitute, Juanjo, pulled it off right away: a goal in the first period.)
- Campo santo: cemetery.
- Espíritu Santo: Holy Spirit, Holy Ghost.
- Guerra santa: holy war.
- Hierba santa: mint (herb).
- Hora santa: prayer given before the Eucharist, or in commemoration of the suffering of Jesus.
- Hueso de santo: a type of almond pastry in the shape of a bone.
- Lengua santa: the Hebrew language.
- Mano de santo: fast and complete cure for an ailment or problem.
- Quedarse para vestir santos: to remain unmarried (said of a woman).
- Santa Faz: an image of the face of Jesus.
- Santa Sede: Holy See.
- Santo de cara: good luck. (Cierto es que no todo el mundo tiene el santo de cara. It's certain that not everyone has good luck.)
- Santo de espaldas: bad luck. (Los habitantes de El Ídolo describen a 1998 con una frase: "Tuvimos al santo de espaldas". The residents of El Idolo describe 1998 with a phrase: "We had bad luck.")
- Santo de pajares: person whose sainthood can't be trusted.
- Santo y seña: military password.
- Semana Santa: Holy Week (the week preceding Easter, including Good Friday).
- Tierra Santa: Holy Land.

