Rectifying valve and Thermionic tube

Rectifying valve noun - A thermionic tube having two electrodes; used as a rectifier.

Thermionic tube and rectifying valve are semantically related. In some cases you can use "Thermionic tube" instead a noun phrase "Rectifying valve".

Thermionic tube noun - Electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope.

Rectifying valve and thermionic tube are semantically related. Sometimes you can replace phrase "Rectifying valve" with "Thermionic tube", this phrases are similar.