Overclocking is pushing a system over its factory specified setting for additional power. Factoried specified settings are recommended for running a system safely without damage from overheat.
The Switch may have a chip that is already pre clocked to a certain limit for max safe performance but may feature some form of software that will raise or lower that limit when certain conditions are met (e.g. when docked). This is not necessarily overclocking but rather the console's chip may be bottle necked when portable and able to freely run at max when docked. The best example is Intel's Turbo Boost which pushes their processor to its pre determined (factory specified) upper limits and lowers the processor when doing less mundane tasks. Intel processors can be overclocked safely with Turbo Boost enabled because Turbo Boost is not overclocking in and of itself.
Hopefully this will help some people understand better and relieve headache for others trying to explain in every post.
Discussion started at here by DaReapa