Definition of "AB"

AB

proper noun
1. Abbreviation of Alberta, a province of Canada.
2. Initialism of Artium baccalaureus.
3. Initialism of Aryan Brotherhood, a US white supremacist, neo-Nazi prison gang and crime syndicate
noun
countable and uncountable, plural ABs
1. Initialism of able seaman; able-bodied seaman.
  Quotations
  In this Ordinance, unless the context otherwise requires— A.B. means an able-bodied seaman […]
  Section 2(1), Merchant Shipping (Seafarers) Ordinance (Cap. 478)
2. Initialism of afterburner.
3. Initialism of aid to the blind.
4. (military, aviation) Initialism of airbase.
5. (organic chemistry) Abbreviation of alkylbenzene.
6. (medicine) Initialism of antibody.
7. Initialism of artificial breeding.
8. (law, politics) Initialism of assembly bill.
9. A blood type of the ABO system that has both blood antigens and may receive all blood types, and donate to AB.
  1. (countable) A person with this blood type.
10. (ABDL) Initialism of adult baby.
11. (Australia, Adelaide, countable) A kind of halal snack pack.
adjective
not comparable
1. Initialism of airborne.
2. Initialism of antiballistic.
3. (baseball) Initialism of at bat.