Source : WordNet®

canonical
     adj 1: appearing in a Biblical canon; "a canonical book of the
            Christian New Testament" [syn: {canonic}]
     2: of or relating to or required by canon law [syn: {canonic}]
     3: reduced to the simplest and most significant form possible
        without loss of generality; "a basic story line"; "a
        canonical syllable pattern" [syn: {basic}, {canonic}]
     4: conforming to orthodox or recognized rules; "the drinking of
        cocktails was as canonical a rite as the mixing"- Sinclair
        Lewis [syn: {canonic}, {sanctioned}]

Source : Free On-Line Dictionary of Computing

canonical
     
        (Historically, "according to religious law")
     
        1.  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.  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".
     
        (2002-02-06)