• Hackney Downs railway station
  Hackney Downs railway station
  Hackney Downs railway station is in the London Borough of Hackney in east London. The station, and all trains serving it, is operated by National Express East Anglia, on the West Anglia route, and it is in Travelcard Zone 2....
  
  , London; National Rail station code HAC
• Le Havre Athletic Club a professional football club in France.
• Hectare
  Hectare
  The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
  
  
• High Acid Crude oil a crude oil with a high concentration of Naphthenic acid
  Naphthenic acid
  Naphthenic acid is the name for an unspecific mixture of several cyclopentyl and cyclohexyl carboxylic acids with molecular weight of 120 to well over 700 atomic mass units. The main fraction are carboxylic acids with a carbon backbone of 9 to 20 carbons. The naphtha fraction of the crude oil...
  
  s
• High-availability cluster
  High-availability cluster
  High-availability clusters are groups of computers that support server applications that can be reliably utilized with a minimum of down-time. They operate by harnessing redundant computers in groups or clusters that provide continued service when system components fail...
  
   (computing)
• Hokkaido Air System Co., Ltd.
  Hokkaido Air System
  , or HAC, is an airline with its headquarters on the property of Okadama Airport in Okadamachō, Higashi-ku, Sapporo. It operates scheduled domestic services in Hokkaidō. Its main base of operations is Okadama Airport.- History :...
  
  
• Honourable Artillery Company
  Honourable Artillery Company
  The Honourable Artillery Company was incorporated by Royal Charter in 1537 by King Henry VIII. Today it is a Registered Charity whose purpose is to attend to the “better defence of the realm"...
  
  
• Hóquei Académico de Cambra
  Hóquei Académico de Cambra
  Hóquei Académico de Cambra is a rink hockey club from Vale de Cambra, Portugal. Its senior team participates in the Portuguese Rink Hockey Championship.-External links:*...
  
  , a rink hockey club from Vale de Cambra, Portugal
• Hospital Acquired Condition
  Hospital Acquired Condition
  A Hospital Acquired Condition is an undesirable situation or condition that affects a patient, that arose during a stay in a hospital or medical facility...
  
  
• Hot adult contemporary, a radio format
• Hughes Aircraft Company
• Human artificial chromosome
  Human artificial chromosome
  A human artificial chromosome is a microchromosome that can act as a new chromosome in a population of human cells. That is, instead of 46 chromosomes, the cell could have 47 with the 47th being very small, roughly 6-10 megabases in size, and able to carry new genes introduced by human researchers...
  
  
• Humanist Association of Canada
  Humanist Association of Canada
  Humanist Canada is a national not-for-profit charitable organization promoting the separation of religion from public policy and fostering the development of reason, compassion and critical thinking for all Canadians through secular education and community support...
  
  
• Humboldt Arts Council
  Humboldt Arts Council
  The Humboldt Arts Council is the official Humboldt County, California, USA arts council, and is located in the Morris Graves Museum of Art ....
  
   - arts council in Humbolt County, California, USA
• Hyles-Anderson College
  Hyles-Anderson College
  Hyles–Anderson College is an unaccredited Bible college in unincorporated Crown Point, Lake County, Indiana, with a postal address at 8400 Burr Street, Crown Point, Indiana 46307-1499. The college is a ministry of the First Baptist Church of Hammond. It focuses primarily on training pastors,...
  
  
• Newey–West HAC estimator - heteroskedasticity- and autocorrelation-consistent estimator
• House Appropriations Committee
  United States House Committee on Appropriations
  The Committee on Appropriations is a committee of the United States House of Representatives. It is in charge of setting the specific expenditures of money by the government of the United States...
  
  , a committee of the United States House of Representatives
• The U.S. Hearing Aid Compatibility Act, 1988
• Heading Alignment Circle
• Hrvatske autoceste, a Croatian motorway operator
• Honorary Air Commodore, a honorary air force position

See also

• Acetic acid
  Acetic acid
  Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...
  
  , often abbreviated HAc or HOAc
• Acetaldehyde
  Acetaldehyde
  Acetaldehyde is an organic chemical compound with the formula CH3CHO or MeCHO. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale industrially. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants as part...
  
  , often abbreviated HAc
• HHC (in the U.S. Army, meaning Headquarters and Headquarters Company
  Headquarters and Headquarters Company
  In United States Army units, a headquarters and headquarters company is a company sized military unit, found at the battalion level and higher. In identifying a specific headquarters unit, it is usually referred to by its abbreviation as an HHC...
  
  ) sometimes pronounced "Hac"