köken: Inherited from Old East Slavic ось (osĭ), from Proto-Slavic *osь (“axle”). In the sense of "operating system", is an adaptation of the English acronym OS in the same sense.
axle (pin or spindle on which a wheel revolves, or which revolves with a wheel; transverse bar or shaft connecting opposite wheels) · shaft, driveshaft (shaft, or long thin object, used to transmit rotary motion) · axis (imaginary line around which an object spins or is symmetrically arranged)
köken: Borrowed from Old Church Slavonic ось (osĭ), from Proto-Slavic *osь (“axle”). Cognates include Bulgarian ос (os), Russian ось (osʹ), Serbo-Croatian os, Czech osa, Polish oś. Doublet of ax and axă.
spindle (rod in spinning and winding thread; rod which turns, or on which something turns round; rotary axis of a machine tool or power tool) · shaft (in an engine) · axle, axletree