polyphase vs multiphase

polyphase and multiphase both are adjectives.

Word	Noun	Adjective	Verb	Adverb
polyphase	No	Yes	No	No
multiphase	No	Yes	No	No

As adjectives, polyphase and multiphase are synonyms defined as:

polyphase and multiphase: of an electrical system that uses or generates two or more alternating voltages of the same frequency but differing in phase angle

polyphase (adjective)	multiphase (adjective)
of an electrical system that uses or generates two or more alternating voltages of the same frequency but differing in phase angle	of an electrical system that uses or generates two or more alternating voltages of the same frequency but differing in phase angle