Bowdler

Etymology
As "de Boelare", the surname dates back to the 11th century, from the name of a town, "Boelare" (now known as "Nederboelare"). Descends from Baldwin de Boelare, who was of a Flemish family and whose surname was variously recorded "de Boulers", "de Boullers", "de Bollers" or "de Bullers" when he came to England, as phonetic variations; this variation appeared later.

Alternatively, from the name of some ancient employment; may be related to buddler.