I did a quick search too, and here's what I came up with.
Etymologically speaking, I think Marvolo may be related to
Malvolio, Italian for "ill will".
However, it may be simply a name needed to make
Tom Marvolo Riddle an anagram of
I Am Lord Voldemort. (Voldemort probably means "flight of death" in French, from the phrase
vol de mort; it's properly pr. VOL-duh-mor as per J.K. Rowling, but is pr. VOL-de-mort in the movies.)
However, in the book, Riddle's was named
Tom after his his maternal grandfather and Marvolo after his maternal great-grandfather.
You do
not want to name your kid Marvolo, however.
Tom Marvolo Riddle grew up to be Voldemort, the
Adolf Hitler-like main villain in
Harry Potter.
See more at the
Harry Potter Lexicon:
http://snipurl.com/fz8v.
Miranda
"Come... you must eat my child." — From a badfic
Proud adopter of 15 punctuation marks; see my profile for their names.