(computing) The tool used by an operating system (OS) to administrate addition, removal and upgrade of software applications. Examples of package management systems on different OSes are: Linux: RPM; Solaris: pkgadd; HP-UX: SD-UX; Debian: apt-get; Win32: Windows Installer.

(neuroanatomy) The part of the autonomic nervous system that raises blood pressure and heart rate, constricts blood vessels, and dilates the pupils when under stress.

(endocrinology) A collection of hormones involved in the regulation of the body's blood pressure and water content

(immunology) The initial line of defense that entails a cascade of cells and mechanisms that protect the host from infection by different organisms in an indeterminate pattern.

(immunology) A system, activated by the innate immune system, that consists of particularly specialized systemic cells and processes that remove or counter pathogenic growth.

(software) Synonym of nominative type system

(programming) A major type system where compatibility and equivalence of data types are determined by explicit declarations or the names of the types.

(travel, aviation) a multi-access reservation system used by the travel industry and airlines.

(object-oriented programming) A concept for computer language types where a primitive type can support methods and encapsulation, but only reference types support virtual methods and specialization.

(computing) Synonym of issue tracking system