• Hydrogen astatide
  Hydrogen astatide
  Hydrogen astatide, also known as astatane, or astidohydrogen is a chemical compound with the chemical formula HAt, consisting of an astatine atom covalently bonded to a hydrogen atom....
  
  

• An informal term for typographic and mathematical symbols
  • caret
    Caret
    Caret usually refers to the spacing symbol ^ in ASCII and other character sets. In Unicode, however, the corresponding character is , whereas the Unicode character named caret is actually a similar but lowered symbol: ....
    
     (^)
  • circumflex
    Circumflex
    The circumflex is a diacritic used in the written forms of many languages, and is also commonly used in various romanization and transcription schemes. It received its English name from Latin circumflexus —a translation of the Greek περισπωμένη...
    
     (ˆ)
• hat operator in mathematical notation
• hat matrix
  Hat matrix
  In statistics, the hat matrix, H, maps the vector of observed values to the vector of fitted values. It describes the influence each observed value has on each fitted value...
  
  
• Hat, Azerbaijan
  Hat, Azerbaijan
  Hat is a village in the Qubadli Rayon of Azerbaijan.Hat is the Azeri village in Qubadli...
  
  , a village
• Hat, Nepal
  Hat, Nepal
  Hat is a village development committee in Baitadi District in the Mahakali Zone of western Nepal. At the time of the 1991 Nepal census it had a population of 1,834 and had 330 houses in the village....
  
  
• Hat District
  Hat District
  Hat District is a district of the Al Mahrah Governorate, Yemen. As of 2003, the district had a population of 2,786 inhabitants....
  
  , a district of the Al Mahrah Governorate, Yemen
• Hat (album), an album by British musician Davy Graham, released in 1969
• Hi-hat
  Hi-hat
  A hi-hat, or hihat, is a type of cymbal and stand used as a typical part of a drum kit by percussionists in R&B, hip-hop, disco, jazz, rock and roll, house, reggae and other forms of contemporary popular music.- Operation :...
  
  , one of the essential cymbals on a drum set
• The Hat
  The Hat
  The Hat is a Southern California fast-food restaurant specializing in pastrami sandwiches. This iconic eatery, once local only to the San Gabriel Valley, has been offering its "World Famous Pastrami" to Southern California residents since 1951. Its customers consume 13 to 15 tons of pastrami per...
  
  , a Southern California fast-food restaurant
• The Hat, the nickname of LSU football coach Les Miles
  Les Miles
  Leslie Edwin "Les" Miles, nicknamed "The Mad Hatter", is an American college football coach and the current head coach of the Louisiana State University football team. Prior to holding that position, he was head coach at Oklahoma State...
  
  
• Hat, The Haskell Tracer, a debugging tool for Haskell programming language
  Haskell (programming language)
  Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing. It is named after logician Haskell Curry. In Haskell, "a function is a first-class citizen" of the programming language. As a functional programming language, the...
  
  
• Former vocalist for the Norwegian Black metal band Gorgoroth
  Gorgoroth
  Gorgoroth is a Norwegian black metal band based in Bergen. Formed in 1992 by Infernus , the band is named after the dead plateau of evil and darkness in the land of Mordor from J. R. R. Tolkien's fantasy novel The Lord of the Rings. The group is currently signed to Regain Records and have released...
  
  

• Hellenic Aeronautical Technologies
  Hellenic Aeronautical Technologies
  HAT is a small Greek aerospace company based in Athens. Its founder, Anastasios Makrykostas has been an aerospace engineer in Hellenic Aerospace Industry. HAT specializes in aircraft parts made of composite materials. The first flight of its own developed aircraft, the HAT LS2, was made on May 23,...
  
  , a Greek airplane manufacturer
• Help authoring tool
  Help authoring tool
  A Help Authoring Tool or HAT is a software program used by technical writers to create online help systems.-Functions:The basic functions of Help Authoring Tools can be divided into the following categories:-File input:...
  
  , software used to create online help manuals
• Histone acetyltransferase
  Histone acetyltransferase
  Histone acetyltransferases are enzymes that acetylate conserved lysine amino acids on histone proteins by transferring an acetyl group from acetyl CoA to form ε-N-acetyl lysine....
  
  , enzymes that acetylate conserved lysine amino acids on histone proteins
• History Aptitude Test
  History Aptitude Test
  The History Aptitude Test is a standardized test used as part of the admissions process to Oxford University for undergraduates applying to read History, or a subject including history, for example English with History....
  
  , administered to students applying to read History at Oxford University
• Human African trypanosomiasis
  Trypanosomiasis
  Trypanosomiasis or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus Trypanosoma. Approximately 500,000 men, women and children in 36 countries of sub-Saharan Africa suffer from human African trypanosomiasis which is caused by...
  
  , diseases caused by parasitic protozoan trypanosomes
• HAT medium
  HAT medium
  HAT Medium is a selection medium for mammalian cell culture, which relies on the combination of aminopterin, a drug that acts as a powerful folate metabolism inhibitor by inhibiting dihydrofolate reductase, with hypoxanthine and thymidine which are intermediates in DNA synthesis...
  
  , a selective medium used in microbiology and immunology
• Verklarende Handwoordeboek van die Afrikaanse Taal, an Afrikaans dictionary
• Hungarian Automated Telescope Network
  HATNet Project
  The Hungarian Automated Telescope Network project is a network of six small fully automated "HAT" telescopes. The scientific goal of the project is to detect and characterize extrasolar planets using the transit method. This network is used also to find and follow bright variable stars...
  
   (HATNet), a telescope network for detecting and characterizing extrasolar planets
• Haitian Creole language
  Haitian Creole language
  Haitian Creole language , often called simply Creole or Kreyòl, is a language spoken in Haiti by about twelve million people, which includes all Haitians in Haiti and via emigration, by about two to three million speakers residing in the Bahamas, Cuba, Canada, France, Cayman Islands, French...
  
   ISO 639 code

See also

• Hats (disambiguation)
• Hatt (disambiguation)
• Het (disambiguation)
• Hett (disambiguation)
• Mr. Hat