Also found in: Dictionary, Thesaurus, Medical, Legal, Wikipedia.
Related to canonical: canonical hours, Canonical form, Canonical name


(science and technology)
Relating to the simplest or most significant form of a general function, equation, statement, rule, or expression.


(Historically, "according to religious law")

1. <mathematics> A standard way of writing a formula. Two formulas such as 9 + x and x + 9 are said to be equivalent because they mean the same thing, but the second one is in "canonical form" because it is written in the usual way, with the highest power of x first. Usually there are fixed rules you can use to decide whether something is in canonical form. Things in canonical form are easier to compare.

2. <jargon> The usual or standard state or manner of something. The term acquired this meaning in computer-science culture largely through its prominence in Alonzo Church's work in computation theory and mathematical logic (see Knights of the Lambda-Calculus).

Compare vanilla.

This word has an interesting history. Non-technical academics do not use the adjective "canonical" in any of the senses defined above with any regularity; they do however use the nouns "canon" and "canonicity" (not "canonicalness"* or "canonicality"*). The "canon" of a given author is the complete body of authentic works by that author (this usage is familiar to Sherlock Holmes fans as well as to literary scholars). "The canon" is the body of works in a given field (e.g. works of literature, or of art, or of music) deemed worthwhile for students to study and for scholars to investigate.

The word "canon" derives ultimately from the Greek "kanon" (akin to the English "cane") referring to a reed. Reeds were used for measurement, and in Latin and later Greek the word "canon" meant a rule or a standard. The establishment of a canon of scriptures within Christianity was meant to define a standard or a rule for the religion. The above non-technical academic usages stem from this instance of a defined and accepted body of work. Alongside this usage was the promulgation of "canons" ("rules") for the government of the Catholic Church. The usages relating to religious law derive from this use of the Latin "canon". It may also be related to arabic "qanun" (law).

Hackers invest this term with a playfulness that makes an ironic contrast with its historical meaning. A true story: One Bob Sjoberg, new at the MIT AI Lab, expressed some annoyance at the incessant use of jargon. Over his loud objections, GLS and RMS made a point of using as much of it as possible in his presence, and eventually it began to sink in. Finally, in one conversation, he used the word "canonical" in jargon-like fashion without thinking. Steele: "Aha! We've finally got you talking jargon too!" Stallman: "What did he say?" Steele: "Bob just used "canonical" in the canonical way."

Of course, canonicality depends on context, but it is implicitly defined as the way *hackers* normally expect things to be. Thus, a hacker may claim with a straight face that "according to religious law" is *not* the canonical meaning of "canonical".


The standard or authoritative method. The term comes from "canon," which is the law or rules of the church. See canonical name and canonical synthesis.
References in periodicals archive ?
Age explained 72% of variation in the multivariate model, with a canonical correlation coefficient of 0.
Canonical is a private company owned by South African Mark Shuttleworth which supports Ubuntu.
n], for any integer vector v, if v is not canonical under G, all children of v are not canonical.
Through our years of working with Canonical, we are able to rapidly support their latest releases, to ensure Ubuntu users can roll out the leading access control and audit solution for organizations using their platform.
Smart Work runs on Canonical s Ubuntu open-source Linux operating system.
If there is a relationship between nutrition and measured characters, multivariate analyses such as canonical correlation analysis (CCA), a technique for describing the relationship between two variable sets simultaneously and to produce both structural and spatial meanings (Thompson, 1984), contribute to layer type hens breeding by providing information based on indirect selection.
But after agonizing hours of discussions at their meeting March 8 to 11, a majority of CoGS members decided that a canonical change "set the bar too high," and would create an impasse in a church already exhausted with the divisive issue that has dragged on for decades.
Though Freeing Celibacy extols the gifts of the spirit that voluntary celibacy can bring, Cozzens surveys the history of married priests in centuries past, clergy sexual abuse scandals and the rapidly declining number of priests today, and concludes that it is time to set celibacy free from canonical mandate to become a graced way of life for some but not all of the church's ordained ministers.
There is only one bishop in the world whose diocese celebrates the traditional Latin liturgy exclusively and who is in full canonical communion with the Holy See.
Holder justifies this in his introduction by emphasizing that these discourses are canonical and therefore constitute the "essential teachings" of the Buddha.
The Vatican will not pursue canonical proceedings, however, because of the 86-year-old Maciel's age.