Definitions of Na:

• noun:   a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
• name:  A female given name (rare: 1 in 100000 females; popularity rank in the U.S.: #3303)
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #13205)