(informal, intransitive) To stop paying attention and think about something else, or to think about nothing

(obsolete, inorganic chemistry) potassium bromide

(obsolete, chemistry) potassium plumbate

A vegetable oil, pressed from sunflower seeds, and used in cooking.

(obsolete, inorganic chemistry) potassium carbonate

(obsolete, inorganic chemistry) potassium chromate

Previously unknown; unprecedented. / Unknown or known to only few people.

A feudal title of the hereditary proprietor of a manor in manorialism; now largely ceremonial.

(Britain, slang) Beer.

(physics) The theories of special relativity and general relativity, two theories in physics developed mainly by Albert Einstein at the beginning of the 20th century from which several important results such as the equivalence of matter and energy and the Einstein field equations are derived.