1.  np(n = noun.substance) atomic number 93, neptunium - a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium;
is a kind of metal, metallic element

2.  np(n = noun.person) nurse clinician, nurse practitioner - a registered nurse who has received special training and can perform many of the duties of a physician;
is a kind of registered nurse, rn

   The chemical symbol for Neptunium, a transuranic element having atomic number 93. [WordNet 1.5]

np, abbr. Notary Public.

np, symb. Chem. the element neptunium.