plugboard vs switchboard

plugboard and switchboard both are nouns.

Word	Noun	Adjective	Verb	Adverb
plugboard	Yes	No	No	No
switchboard	Yes	No	No	No

As nouns, plugboard and switchboard are synonyms defined as:

plugboard and switchboard: telephone central where circuits are completed with patchcords

Other synonyms of plugboard include patchboard.

plugboard (noun)	switchboard (noun)
telephone central where circuits are completed with patchcords	telephone central where circuits are completed with patchcords