Many of those familiar with J.K. Rowling's Harry Potter books, or the films based on them, have been surprised to discover that the name of the headmaster of Hogwarts School also occurs in Tolkien's writings. (They might be even more surprised to find it in Thomas Hardy's The Mayor of Casterbridge.) The word is recorded by the OED as a dialect name for the bumblebee (and certain other insects), with quotations dating back to 1787. Tolkien used it in some versions of his poem "Errantry", in which the 'merry passenger', we are told, "battled with the Dumbledores" (History of Middle Earth VII. 86, 88).
He battled with the Dumbledores,
the Bumbles, and the Honeybees,
and won the Golden Honeycomb;
and running home on sunny seas
in ship of leaves and gossamer
with blossom for a canopy,
he polished up, and furbished up,
and burnished up his panoply.
The Ring of Words - Tolkien and the Oxford English Dictionary (OUP - 2006)
Posted by Arborfield at 7:34 am