Wizards, Witches and Beings: N
Gryffindor House ghost. The nickname of the ghost of Sir Nicholas de Mimsy Porpington, a wizard who died in a botched execution on October 31, 1492. (More...)
Madam Z. Nettles of Topsham, along with D.J. Prod, was apparently a happy customer of Argus Filch's Kwikspell course. Before Kwikspell, she "had no memory for incantations and my potions were a family joke!" (CS8)
Nigellus, Phineas (SEE Black, Phineas Nigellus)
The word "not" has an obvious negative connotation, which is fitting for a Death Eater. See entry below for more possibilities.
(b. circa 1980)
Slytherin, 1991 - 1998 (PS7, OP26)
Son of the Death Eater Nott, Theodore is described as "weedy-looking" (OP26) and “a clever loner who does not feel the need to join gangs, including Malfoy’s.” He can see thestrals (JKR).
Nott's name could have many different meanings: nothing (as in 'naught'), and binding (as in 'knot'). In Norse myth, Nott is the "personification of night, and the daughter of Narvi. Nott's chariot is pulled by the horse Hrimfaxi ('frost-maned') which covers the earth with dew early in the morning." (EM).
(1665 - 1743)
Honoria was Wizard of the Month on Rowling's website for August, 2004 (JKR).