- a digest or summary, esp of laws
- an introduction to legal study in ancient Rome, compiled by order of Justinian and divided into four books forming part of the Corpus Juris Civilis
- short for Institutes of the Christian Religion, the book by Calvin, completed in 1536 and constituting the basic statement of the Reformed faith, that repudiates papal authority and postulates the doctrines of justification by faith alone and predestination
