The union of three persons (the Father, the Son, and the Holy Ghost) in one Godhead, so that all the three are one God as to substance, but three persons as to individuality.
- A group consisting of three closely related members. Also called triunity.
- Theology In most Christian faiths, the union of three divine persons, the Father, Son, and Holy Spirit, in one God. Also called Trine.
- Trinity Sunday.