Initialism of Bachelor of Arts. / Initialism of Business Analyst. / (Internet, security) Initialism of Basic Authentication.

Initialism of British Airways. / Initialism of Buenos Aires. / (overprint on British stamps) Initialism of British Administration (usually followed by a place name).

(euphemistic) Initialism of bad-ass.

(Egyptian mythology) A being's soul or personality, represented as a bird-headed figure, which survives after death but must be sustained with offerings of food.

(colloquial and in direct address) Father, baba.

(historical) A medieval football game played in parts of Scotland around Christmas and New Year.

Abbreviation of bathroom.

(music, Japan) Abbreviation of bass guitar (of a rock band)

Alternative form of ba (“medieval football game played in Scotland”)

(pharmacology) a shortened allomorph of the monoclonal antibody affix -bac-, used before the affixes -xi- and -zu- for ease of pronunciation