prior

Less common meanings

4. 4
   nouncountable

   A man who heads a priory, a house of friars, or certain religious orders, or the monk next below the abbot in an abbey; also an honorary title in some military religious orders.

   The prior administered the daily affairs of the priory.

   The twelve monks of the small hillside monastery elected a new prior last spring.

   Note

   The title covers two roles. A prior conventual is in charge of a priory, while a prior claustral serves as the abbot's deputy in an abbey. The same title can therefore mark the second-in-command in one community and the superior in another. Which one is meant usually depends on whether the house is an abbey or a priory.

5. 5
   nouncountable

   In Bayesian statistics, a probability distribution expressing what is believed about a quantity before the evidence now being considered is taken into account.

   The analyst updated the prior as new measurements arrived.

   Choosing an informative prior shaped the model's conclusions.

   Oppositeposterior

   Note

   Bayesian shorthand turns the statistician's adjective into a noun, so that a prior probability distribution becomes simply "a prior." Its paired opposite is the posterior. The prior represents the distribution before additional evidence is taken into account, and the posterior is what the analysis yields once that evidence is included. The two words name the two ends of a single Bayesian update. Source

   Checked 1 Nov 2026 · 4 facts

   • The noun 'prior' is shorthand for a prior probability distribution. ucl.ac.uk
   • The corresponding opposite is the posterior. en.wiktionary.org
   • A prior represents the distribution before the evidence under consideration is incorporated; this need not precede its collection. cpd.berkeley.edu
   • The posterior is the distribution resulting from incorporating the data, completing the update from the prior. web.stanford.edu
6. 6
   initial (probability)adjective

   Of a probability: assigned before the evidence now being considered is taken into account, though it may draw on earlier data or background knowledge.

   The model began with a prior probability based on past seasons.

   Using Bayes' rule, she combined the prior probability with the new test results.

   Oppositeposterior

   Note

   Statisticians use this adjective in phrases such as prior probability, prior distribution, and prior predictive check. It marks where a probability stands in the order of reasoning, which is before the evidence now being considered is taken into account. It does not mean that the probability is more important, despite the "precedence" meaning. In Bayesian work, "prior" always answers the question "before what?" Source

   Checked 1 Nov 2026 · 3 facts

   • Other standard statistical expressions include 'prior distribution', 'prior belief', and 'prior predictive check'; the claimed restriction is too strong. mc-stan.org
   • It precedes incorporating the particular evidence into the reasoning, rather than necessarily preceding the evidence's arrival. cpd.berkeley.edu
   • Statistical 'prior' concerns the evidence relative to which a probability is specified, rather than greater importance. en.wikipedia.org
7. 7
   nouncountable

   A belief or assumption, based on past evidence or experience, that someone brings to a question and may revise when new evidence arrives.

   He admitted his prior about the market was based on a single bad year.

   Strong evidence forced her to revise a long-held prior.

   UsageCommon phrases are update your priors, check something against your priors, and have your priors confirmed.

   Similarbelief, assumption, preconception

   Oppositeposterior

   Note

   Here the Bayesian noun has moved into everyday argument, mostly in the plural. An investor checks each data point against his priors, and a political writer announces that "our priors are confirmed." What it names is a settled expectation, not a calculated distribution, and the word lends ordinary judgment a borrowed air of statistical rigor. Source

   Checked 1 Nov 2026 · 3 facts

   • The informal belief sense extends the Bayesian noun. en.wiktionary.org
   • An investor describes checking incoming data against his priors. en.wiktionary.org
   • A political writer uses the exact words “our priors are confirmed”: Alex Shephard in The New Republic. newrepublic.com
8. 8
   first in importanceadjective

   More important or significant than other things; having precedence over them.

   The bank's loan had a prior claim on the money from the sale of the house.

   Family duties had a prior claim on his weekends, so the fishing trip had to wait.

   UsageMost often in the phrase a prior claim on something or someone.

   Similarpreferential, overriding, paramount, primary

   Oppositesecondary, subordinate

   Note

   The figurative side of the Latin word survives here. Latin prior could mean "better, superior" as well as "earlier," and this sense keeps the ranking without the timing. A prior claim comes first because it counts for more, not because it came sooner. Source

   Checked 2 Nov 2026 · 1 fact

   • English prior derives from Latin prior, whose meanings included “earlier” and figuratively “better, superior.” en.wiktionary.org
9. 9
   nounobsolete

   (obsolete) A leader or chief, such as the head of a company or the foremost figure in a field of activity.

   Note

   It called the foremost figure in a field its prior. The idea of rank goes back to the "better, superior" side of Latin prior, the same ranking found in the "more important" adjective. Read it as leader or chief, since a modern reader would take it otherwise. Source

   Checked 2 Nov 2026 · 2 facts

   • The noun's sense of rank derives ultimately from Latin prior, which could mean better or superior. en.wiktionary.org
   • The English adjective prior also has a sense expressing greater importance. en.wiktionary.org
10. 10
    nounrare

    In certain cathedrals, an honorary title bestowed on one of the priests.
11. 11
    noun

    One of the chief magistrates of the Republic of Florence, chosen from the guilds, who governed from the late thirteenth century until 1532.
12. 12
    noun

    In some European and South American countries, the head of a craft or merchant guild, chosen by its members.