Np

symbol

the chemical element neptunium.

abbreviation, noun

notary public.

1. new paragraph.
2. no place of publication (used especially in book classification).

noun, symbol

the chemical element of atomic number 93, a radioactive metal of the actinide series. Neptunium was discovered as a product of the bombardment of uranium with neutrons, and occurs only in trace amounts in nature.

late 19th century: from Neptune, on the pattern of uranium (Neptune being the next planet beyond Uranus).