Absorbance Units, a reporting unit in spectroscopyAstronomical unit, the average distance between the Earth and the Sun (roughly speaking)Atomic units, a system of units convenient for atomic physics and other fieldsGold, a chemical element with the symbol AuArbitrary unit, a relative placeholder unit for when the actual value of a measurement is unknown or unimportant
Computing
.au, the internet country code for AustraliaAu file format, Sun Microsystems' audio formatAudio Units, a system level plug-in architecture from Apple ComputerAdobe Audition, a sound editor program.Automatic Updates, also known as Windows Update.
Universities
Aarhus University, DenmarkAberystwyth University, Wales, United KingdomAdelphi University, New York, United StatesAir University (disambiguation), various locationsAletheia University, New Taipei City, Republic of ChinaAlfred University, New York, United StatesAlgoma University, Sault Ste. Marie, ON, CanadaAllahabad University, Uttar Pradesh, IndiaAmerican University, Washington, DC, United StatesAnderson University (Indiana), United StatesAnderson University (South Carolina), United StatesAndhra University, Visakhapatnam, AP, IndiaAndrews University, Michigan, United StatesArellano University, PhilippinesAthabasca University, Alberta, CanadaAuburn University, Alabama, United StatesAuckland University, New ZealandAurora University, Aurora, IL, United States
Geography
AustraliaAu (Munich), Munich, GermanyAu (Schwarzwald), Baden-Württemberg, GermanyAu am Leithaberge, AustriaAu am Rhein, GermanyAu, Guinea, Kankan RegionAu im Bregenzerwald, AustriaAu in der Hallertau, GermanyAu peninsula, SwitzerlandAu, St. Gallen, SwitzerlandAu, Vorarlberg, Bregenz, AustriaAu, Zurich, Switzerland
Organizations
African Unionau (mobile phone company), a mobile phone company in JapanAkademia Umiejętności, a primary Polish scientific institutionAmericans United for Separation of Church and StateAustral Líneas Aéreas, IATA code
Surname
Au (surname), a Chinese family name
Miscellaneous
Au Co, a fairy in Vietnamese mythologyAb urbe condita (sometimes abbreviated as a.u.), Latin for "from the founding of the City" (Rome)Alternative universe (fan fiction)Athletic Union, the union of sports clubs in a British universityAu (building), a building that has been squatted in in Frankfurt, GermanyAú, a cartwheel in the Brazilian martial art of CapoeiraAU (band), an experimental pop group headed by Luke WylandAu (album), a 2010 release by Scottish rock band Donaldson, Moir and PatersonFord AU Falcon, a family car made in AustraliaAlternative Ulster, a music magazineVought AU, post-WWII US Marines variant of the F4U corsair