"computer operating system using a disk storage device," 1967, acronym of disk operating system.
1580s, "natural science, the science of the principles operative in organic nature," from physic in sense of "natural science." Also see -ics. Based on Latin physica (neuter plural), from Greek ta physika, literally "the natural things," title of Aristotle's treatise on nature. The current restricted sense of "science treating of properties of matter and energy" is from 1715.
Before the rise of modern science, physics was usually defined as the science of that which is movable, or the science of natural bodies. It was commonly made to include all natural science. At present, vital phenomena are not considered objects of physics, which is divided into general and applied physics. [Century Dictionary, 1895]
computer software company, founded 1975 by Bill Gates and Paul Allen.