Science and engineering
* abbreviation for orchid genus ''Paphinia'' * Pacific–North American teleconnection pattern, a climatic phenomenon * Parisiensia Nomina Anatomica, the revision of anatomic nomenclature * Peanut agglutinin, a lectin specific for Gal-β(1-3)-GalNAc * Peptide nucleic acid, an artificially synthesized polymer similar to DNA or RNA. * Plastic neutral axis, an engineering value used in plastic section modulus * Pottery Neolithic A, a division of the Pottery Neolithic period in archaeologyOrganizations
* Pakistan National Alliance * Palestinian National Authority, an administrative autonomous government in parts of the West Bank and the Gaza Strip * Project for Nuclear Awareness, a non-profit organization that advocates for the abolition of nuclear weapons, co-founded by John C. Haas * Polish National Alliance, a non-profit organization, the largest Polish – American Fraternal Benefit Society in USA offering life insurance and annuities. Founded in 1880, operates solely for the benefit of its members. *Pa-O National Army * ''Partido Nueva Alianza'', the Spanish name for the New Alliance Party (Mexico) * Parties to the Nauru Agreement * Pennsylvania NewsMedia Association * Philippine Nurses Association * ''Prefectura Naval Argentina'', the Spanish name for the Argentine Naval Prefecture * National Anticorruption Directorate, Romania; formerly, National Anticorruption Prosecution Office (PNA)Computing
* HomePNA, a home-computer networking standard * Personal navigation assistant (PNA)Other
* Pacific Northern Airlines, acquired by Western Airlines in 1967 * Pamplona Airport * Partial nail avulsion, a treatment of Ingrown nail#Nail avulsion, ingrown toenails * Philippine News Agency * Prenuptial agreement, a marriage contractSee also
*PNAS, Proceedings of the National Academy of Sciences of the United States of America *PnaS, Phosphate-Sodium Symporter, a sodium/phosphate cotransporter * Protected Natural Area (disambiguation) {{disambiguation.svg.html){kind=link}