GAA

• Glacial (water-free), acetic acid • Acid alpha-glucosidase, also known as glucosidase, alpha; acid, an enzyme • a codon for glutamic acid ==Government==

• GADA 601, Argentine Army unit Grupo de Artillería Antiaérea 601 (Anti-Aircraft Artillery Group 601) • General Allotment Act, US law passed in 1887 regarding Indian land • Group Areas Acts, South African apartheid laws • General Appropriation Act, the legislative act used in some countries for a national or state budget ==Organisations==

• Gaelic Athletic Association, governing body of Gaelic games such as hurling and Gaelic football • Gay Activists Alliance, New York City gay rights organisation 1969–81 • Gemmological Association of Australia, an educational organisation based in Sydney • Global Accounting Alliance, an accounting organisation • Global Aquaculture Alliance, an international non-profit trade association • Grenada Athletic Association, the governing body for the sport of athletics in Grenada • Guam Adventist Academy, a private school in Guam ==Other uses==

• Gaa language, a language of Nigeria • Ga'a, a military leader in the ancient Oyo Empire in West Africa • gaa, the ISO 639 code for the Ga language of Ghana • GAA, the ICAO airline code for Business Express Airlines • Gaelic football, an Irish team sport commonly known as GAA • Generic Authentication Architecture, a mobile phone specification • Goals against average, goalkeeping statistic used by several sports and many leagues • Ford GAA engine • Gate-all-around, a specific type of 3D transistors