(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.

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

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

(computing, historical) A type of computer system, now largely obsolete, used to exchange messages and data over a telecommunications network.

Alternative letter-case form of sysop.

(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.

(derogatory) Preceded by the word the: the mainstream culture, controlled by the elites or government of a state, or a combination of them, seen as oppressive to the individual.

A system of measurement in use in the United Kingdom and other Commonwealth countries, now mostly superseded by the metric system; similar to the system currently used in the United States; consisting of units such as the inch, the mile and the pound (of weight).

(computing, Internet) A system operator, especially someone who administers an online communications system or bulletin board. / (Wikimedia jargon) An administrator on a wiki.