Slew

Slew is a verb with several senses relating to rotation and turning. In engineering and everyday usage, to slew something means to rotate it around a vertical axis, or to swing it through a wide arc. This motion is common for equipment that needs directional aiming, such as crane booms, radar antennas, gun turrets, or telescope mounts, where precise angular movement is controlled by motors or gears.

As a noun, slew most often refers to a large number or quantity, as in a "slew of options." This informal usage is widespread in written and spoken English. In technical contexts, the term also describes the mechanical assembly that enables rotation: a slewing bearing (also called a slewing ring) supports the rotational movement of a platform or structure.

In astronomy and instrumentation, to slew means to move a device to a new target or coordinate. Telescopes, cameras, and robotic arms perform slewing motions to reframe their view or align with a task.

In electronics and control systems, slew rate is the maximum speed at which an output can change, typically expressed in volts per microsecond. Slew rate limits affect signal integrity in amplifiers, digital-to-analog converters, and high-speed interfaces. In robotics and machinery, slewing describes the controlled rotation of a platform or component about its rotary axis.