TN

Tn or TN may refer to:

Businesses and organizations

• Air Tahiti Nui (IATA airline designation "TN" since 1998), a French Polynesian airline
• Texas and Northern Railway, an American railway (reporting mark "TN")
• Todo Noticias, an Argentine cable news network
• Trans Australia Airlines (IATA airline designation "TN" until 1994), a defunct Australian airline
• Transports en commun de Neuchâtel et environs, a public transport operator in Neuchâtel, Switzerland

Places

• Tamil Nadu, a state in southern India (ISO abbreviation "IN-TN")
• Tennessee, US (postal abbreviation "TN")
• Tonbridge, a region in England (postcode "TN")
• Tunisia (ISO 3166-1 country code "TN")
• Trentino, a province in Italy (ISO abbreviation "IT-TN")
• North Tipperary, a former county of Ireland (car plate code "TN")

Science and technology

• .tn, the country code top level domain (ccTLD) for Tunisia
• TN network, a type of earthing system for protection in electricity network
• Neel Temperature, the temperature at which an antiferromagnetic material becomes paramagnetic (represented as T_N)
• Tetraodon, a genus of pufferfish
• Trigeminal neuralgia, a neuropathic disorder
• Transposon (when immediately followed by a number), a DNA sequence that can change positions
• Twisted nematic field effect, the technology that made LCD displays practical
• Thoron, symbol Tn, a sometimes used name for the nuclide radon-220

Other uses

• TN status ("Treaty national", or "Trade NAFTA"), an immigration status of a Canadian or Mexican citizen working in the USA under the NAFTA agreement
• Telephone number, in the telecommunications industry
• Tom Next (or Tomorrow Next), a financial trade which starts tomorrow and settles in the next trading day
• Trillion ("TN" or "tn"), a number equal to 10¹² (short scale) or 10¹⁸ (long scale)
• Tswana language (ISO 639-1 language code)
• Translators Note ("TN" or "t/n")
• Turbonave, an Italian ship prefix, indicating that the ship was propelled by a turbine engine.