(healthcare) The medical attention that a patient receives upon first contact with a healthcare system; either a general practitioner or the A&E or ER department of a hospital.

(psychology) A consequence, such as food or water, that fulfills a primary, unlearned drive, such as hunger or thirst, and thereby reinforces a behavior without dependence on prior learning.

(chemistry) in a coordination compound, the number of negative ions needed to satisfy the charge on the central metal ion

(chemistry) any compound of general formula R-PH₂

A person or organization producing basic agricultural commodities, such as a farmer or cattle producer.

Hypothermia caused by exposure to a cold environment.

The organic matter produced from carbon dioxide by photosynthesis

Goods which are presumed to be desired by all rational individuals.

Synonym of primary source

(law) legislation enacted by an act of parliament; contrasted with secondary legislation, which is enacted by the executive branch under powers derived from primary legislation.