1610s, "the whole creation, the universe," from Late Latin systema "an arrangement, system," from Greek systema "organized whole, a whole compounded of parts," from stem of synistanai "to place together, organize, form in order," from syn- "together" (see syn-) + root of histanai "cause to stand," from PIE root *sta- "to stand, make or be firm."
Meaning "set of correlated principles, facts, ideas, etc." first recorded 1630s. Meaning "animal body as an organized whole, sum of the vital processes in an organism" is recorded from 1680s; hence figurative phrase to get (something) out of one's system (1900). Computer sense of "group of related programs" is recorded from 1963. All systems go (1962) is from U.S. space program. The system "prevailing social order" is from 1806.
library classification system that organizes information into 10 broad areas subdivided numerically into progressively smaller topics, by 1885, named for Melvil Dewey (1851-1931) who proposed it 1876 while acting librarian of Amherst College. He also crusaded for simplified spelling and the metric system.
"computer operating system using a disk storage device," 1967, acronym of disk operating system.
also metre, "fundamental unit of length of the metric system," originally intended to be one ten-millionth of the length of a quadrant of the meridian, 1797, from French mètre (18c.), from Greek metron "measure," from PIE root *me- (2) "to measure." Developed by French Academy of Sciences for system of weights and measures based on a decimal system originated 1670 by French clergyman Gabriel Mouton.
"pertaining to the system of weights and measures based on the meter," 1855, from French métrique, from mèter (see meter (n.2)). In this sense, metrical is attested from 1797. Metric system is attested by 1855.