prior

Prior is a term with several related senses in English. As an adjective, it means earlier in time or preceding; the word derives from the Latin prior, meaning "earlier" or "former". It is commonly used in phrases such as "prior to" to indicate something that comes before another thing.

In religious contexts, a prior is a monastic officer. A priory is a monastery or house headed by a prior, who is typically subordinate to an abbot. In some orders the prior acts as the community’s superior, while in others the abbot remains the head with the prior as second-in-command. The female counterpart is the prioress.

Historically the title appears across medieval Christian communities in Europe and was shaped by monastic reforms such as the Benedictines and Cluniacs. The term also appears in various ecclesiastical charters and legal documents, reflecting its role as a position of leadership within a religious house.

In statistics, "prior" refers to a prior distribution in Bayesian inference. It encodes beliefs about a parameter before data are observed and, together with the likelihood, produces a posterior distribution. Priors may be informative or noninformative, and they are chosen to reflect prior knowledge or to regularize estimates.

In law and criminal justice, "prior" is used to denote a previous conviction or offense, as in "prior convictions". This history can influence sentencing, parole eligibility, or risk assessments. The term also exists as a surname and as a toponymic or occupational name in English-speaking regions.

See also priory and the phrase prior to.