Definition of "canonical"

In a word, they were made uſe of by the immediate ſucceſſors of the Apoſtles, and many of them read in the Public Aſſemblies of Chriſtians, as Canonical Scripture, without the leaſt mark of Diſtinction, in point of Autority […]

1732, George Reynolds, A diſſertation: or, Inquiry Concerning the Canonical Autority of the Goſpel according to Mathew; […] ‎, 2nd edition, page 4

While bills are being brought into the House of Commons to regulate every thing, from the sweeps crying "sweep," to "emancipation, vote by ballot, and free trade," is there no county member whose "time and talents" are devoted to "domestic policy," who will bring in a bill "for the better regulation of the marriage ceremony," and put the canonical hours later in the day?

1838 (date written), L[etitia] E[lizabeth] L[andon], “(please specify the page)”, in Lady Anne Granard; or, Keeping up Appearances. […], volume I, London: Henry Colburn, […], published 1842, pages 158–159

It turns out that ordered pairs can be defined in set theory, e.g. as ( x , y ) := { { x , y } , y } {\displaystyle (x,y):=\{\{x,y\},y\}} . Note that in no sense is such a definition canonical.

2011 February 7, Samson Abramsky with Nikos Tzevelekos, “Introduction to Categories and Categorical Logic”, in (Please provide the book title or journal name)‎, page 19

He, good man, could make but little of his solitary friend, and must many a time have been startled out of his canonicals by the strange, alien speeches which he heard.

1857, Various, The Atlantic Monthly, Volume 1, Issue 2, December, 1857‎

Mr Altham rose, as in duty bound, in honour to a priest, and a priest who, as he dimly discerned by his canonicals, was not altogether a common one.

1891, Emily Sarah Holt, The White Lady of Hazelwood‎

When I was a boy I was a passionate atheist, I defied God, and so far as God is the mere sanction of social traditions and pressures, a mere dressing up of the crowd's will in canonicals, I do still deny him and repudiate him.

1915, H. G. Wells, The Research Magnificent‎

Google advises canonicals as one of the preferred methods of treating duplicate content in your CMS.

2015, Simon Kloostra, Joomla! 3 SEO and Performance, page 63