Neighborhood association (see neighbourhood)

North America

Sodium, chemical element

Narcotics Anonymous

Neurotics Anonymous

The Virgin New Adventures series of Doctor Who novels

Hey Jude

National Association of Professional Baseball Leagues (minor league baseball since December 1901)

Nucleic acid

Avogadro's number — abbreviated to N_A

Na (surname), a Korean family name

National Association of Professional Base Ball Players (the sole professional "league" 1871-1875)

Numerical aperture — a specification in optical systems

Nestle-Aland

Na Na Na Na Naa

Norfolk Academy

Neo-Aramaic languages

Naturally-aspirated engine (Normally-aspirated engine)

Na (play), a play by the Indian playwright Anand Gandhi

Land of a Thousand Dances

Not Available (frequently written "n/a")

Na (kana), the な or ナ kana in the Japanese language

One of several National Alliances

One of several Northern Alliances

Na Na

The name of a tribal people of Arunachal Pradesh. See Nga people

The name of a small ethnic group living in Yunnan and Sichuan Provinces in China. See Mosuo

Na (tree), Mesua ferrea a tree native to Sri Lanka, India, southern Nepal, Indochina, and the Malay Peninsula.

Namibia (ISO country code)

New Africa — a North American Black nationalist group

North American Airlines — IATA airline designator

Not Applicable (frequently written "n/a")

N.A. was a Manhattan(New York) Nightclub, named after its owner Noel Ashman. The club is now closed and the space houses The Plumm. It was once the home of Nell's

Nanoampere, an SI unit of electric current (defined as 10⁻⁹ A)