(anatomy) In mammals, including humans, a network of lymph vessels and lymph nodes that transport fluid, fats, proteins, and lymphocytes to the bloodstream as lymph, and remove microorganisms and other debris from tissues.

An organ system that coordinates the activities of muscles, monitors organs, constructs and processes data received from the senses, and initiates actions.

(astronomy) A group of stars (and possibly smaller bodies such as planets or asteroids) that orbit one another.

The system of units developed in France in the 1790s and now used worldwide.

Any collection of heavenly bodies including a star or binary star, and any lighter stars, brown dwarfs, planets, and other objects in orbit.

Alternative letter-case form of Solar System; the Sun and all the objects in orbit around it.

A system of measurement in use in the United Kingdom and other Commonwealth countries, now mostly superseded by the metric system; similar to the system currently used in the United States; consisting of units such as the inch, the mile and the pound (of weight).

(software) Software for controlling the allocation and use of various hardware resources (memory, CPU time, disk space, input and output devices) to tasks and remote terminals.

Any device with inner workings obscured.

A system used to determine the result of an election based on the preferences expressed by voters.