noun
intermediate switch; crossover switch; four-way switch
Electrical switch used in multi-location lighting circuits, known as an intermediate or crossover switch in the UK and a four-way switch in the US. Compare ４路スイッチ.
See also: ４路スイッチ (よんろスイッチ)
この階段の照明にはＤスイッチが使われている。
An intermediate switch is used for the lighting on this staircase.
Ｄスイッチは３路スイッチと組み合わせて使う。
A four-way switch is used in combination with three-way switches.