A combination of two or more sets generally physically separated when in operation, and such other assemblies, subassemblies, and parts necessary to perform an operational function or functions.

A combination of several pieces of equipment integrated to perform a specific function; thus a fire control system may include a tracking radar, computer, and gun.

1. A major time-stratigraphic unit of worldwide significance, representing the basic unit of Phanerozic rocks.

2. A group of related structures, such as joints.

3. A chronostratigraphic unit, below erathem and above series.

A region in space or a portion of matter that has a certain amount of one or more substances, ordered in one or more phases.

A method of organizing entities or terms; in particular, organizing such entities into a larger aggregate.