Henrietta and Thomas Bowdler were an English sister and brother who prepared and published an 1807 edition of Shakespeare’s works that was meant to be appropriate for women and children and for families to read together. To accomplish this, they removed or changed many words, phrases, and passages they believed to be racy or offensive. This is the origin of the verb bowdlerize, which means to remove elements considered offensive (from a literary work or other work of art).
Bowdlerization is similar to censorship, but more narrowly defined. Censorship is often official, often politically motivated, and often applied to nonartistic texts, while bowdlerization is usually done by a private individual or group seeking to make a work of art more morally acceptable. Also, censorship often involves outright removal of parts of texts, while bowdlerization often involves cleaning things up but not removing them. The word tends to have negative connotations. Bowdlerizers typically use other terms to describe what they do.
In British writing, bowdlerize and bowdlerise were both used from early in the word’s history (the early 19th century), and neither has faded out of use. Some U.K.-centered English reference sources, including the Oxford and Cambridge dictionaries, list the -ize spelling as primary, and an ngram graphing British use of both spellings since 1850 shows bowdlerize has been favored through most of its history. Still, British English usually favors -ise over -ize for words not rooted in Greek, so it’s not surprising that bowdlerise appears often.
Non-U.K. English speakers from outside North America are similarly noncommital between bowdlerise and bowdlerize. Examples of both are easily found in Australian and New Zealand publications, for instance. Meanwhile, Americans and Canadians favor bowdlerize with only rare exceptions.
To our astonishment it is omitted, for reasons, perhaps, satisfactory to those who would “Bowdlerize” the ancient poets, but very vexatious in the present instance, as depriving us of any indication which way Mr. Conington would have dealt with this Ode. [The English Journal of Education (1863)]
And, as much as possible, Bowdlerising should be avoided. It oftener does harm than good; it gives a marked importance to what might pass unnoticed, and substitutes unwholesome curiosity for indifference. And you cannot Bowdlerise life. [A Housewife's Opinions, Augusta Webster (1879)]
If coeducation becomes a fact, which horn of the dilemma will you take? Will you Bowdlerize classical literature, and will you expurgate the university curriculum, or will you teach your women students to hear and discuss, in the presence of men, subjects to which no modest woman can, under such circumstances, listen without a blush? [The American: A National Journal (1882)]
Is there not more than once—e.g. in regard to flat worms and gapes-worms—a distinct and deplorable tendency to bowdlerise the elementary facts of sex? [Nature (1921)]
From 1863 on, Baudelaire had to confront the clumsy attempts, sometimes successful, of excessively modest publishers to bowdlerize the prose poems. [1968 intro to Baudelaire's Petits poèmes en prose]
That will free up your unscrupulous writers … to bowdlerize the story of a romance between a 19th-century English schoolteacher and the polygamous King of Siam. [Washington Post (1999)]
The subject was how your parents, to bowdlerise Philip Larkin, mess you up. [Telegraph (2010)]