Any authority which has a legal mandate to govern, administrate a part or aspect of public life, such as all branches of the executive power of a state, province, municipality etc.

plural of public authority

The whole of such public authorities, the governmental administration in the widest sense

public relations (in attributive use)

The aspects of social life which occur in public, in the open, as opposed to more private social interaction within families, private clubs, etc. / Politics, as in the profession of being a politician.

(pathology) The accumulation of fluid in the tissue of the lungs.

A machine used to keep blood and lymph flowing by pushing air through bands or sleeves that are placed on the arms or legs.

(UK) A pudding made from apples and Victoria sponge cake mixture.

(earth science) The collection of biological ocean processes that regulate the uptake, storage, and release of carbon.

Alternative form of it's not the whistle that pulls the train