Ha

Ha may refer to:

Science and measurement

• Hahnium, an element now called Dubnium
• Hartree, an atomic unit of energy
• Hectare (ha), a unit of area
• Hectoampere, a unit of electric current
• Hour angle, in astronomy, one of the coordinates of the equatorial coordinate system
• Hyaluronan (Hyaluronic acid), a carbohydrate structure
• Hydroxylapatite, a mineral
• High availability, systems design and implementation with a view to maximising service

Medicine

• Hyperandrogenic anovulation, also called polycystic ovary syndrome
• Hemagglutinin (influenza) (HA), an antigenic glycoprotein from Influenza viruses
• Hemagglutination assay, a measurement of viruses or bacteria

Linguistics

• Hausa language, ISO 639-1 code HA
• Ha language, the language of the Ha people in eastern Africa
• Ha (kana), in syllabic Japanese script
• Hāʼ, a letter in the Arabic alphabet
• Ha (Javanese) (ꦲ), a letter in the Javanese script

Mathematics

• ha (function prefix) (half), a prefix for some trigonometric functions in mathematics

Media

• Ha (Talvin Singh album), 2002
• Ha (Doseone album), 2005
• Ha! (Killing Joke album), 1982
• "Ha" (song), by Juvenile
• Ha! (TV channel), an American all-comedy TV channel
• The Jim Henson Company, formerly known as ha!

Transportation

• Hawaiian Airlines, IATA designator HA
• Highways Agency, part of England's Department for Transport
• British Rail Class 71, a locomotive

Geography

• Ha, Bhutan
• HA postcode area, a group of English postal districts in north-west London
• Ha Gorge, Greece
• Hå, Norway

Title

• Ha people, Tanzanian people
• Ha (mythology)

Surnames

• Xia (surname) (夏), romanized Ha in Cantonese and Korean
• Ha (哈), a Chinese surname
• Hà, Vietnamese surname 河
• Hạ, Vietnamese surname 賀
• Hà, Ho, Vietnamese surname 胡
• Hạ, Vietnamese surname 夏
• Ha (河), Korean surname
• Ha (賀), Chinese and Korean surname

People

• Ha Hee-ra (夏希羅), Korean actress
• Haha (entertainer), Ha Dong Hun (河東勳), Korean singer
• Ha Seung-Jin, Korean basketball player
• Ha Seok-jin, Korean actor

Other uses

• Health authority
  • Johnstone v Bloomsbury HA
  • Bolitho v City and Hackney HA
  • Hotson v East Berkshire Area HA
• Hells Angels, a motorcycle gang
• Heritage Auction Galleries
• HockeyAllsvenskan, the second-tier league in ice hockey in Sweden
• Hong Kong Housing Authority
• Hospitalman Apprentice, a U.S. Navy rank
• Homosexuals Anonymous, an ex-gay program for dealing with unwanted same-sex attractions
• Human Action, a book by the Austrian economist Ludwig von Mises

See also

• Haha (disambiguation)
• Has (disambiguation)
• Haa (disambiguation)