past perfect vs pluperfect

past perfect and pluperfect both are nouns.

Word	Noun	Adjective	Verb	Adverb
past perfect	Yes	No	No	No
pluperfect	Yes	Yes	No	No

As nouns, past perfect and pluperfect are synonyms defined as:

past perfect and pluperfect: a perfective tense used to express action completed in the past

Other synonyms of past perfect include past perfect tense, pluperfect tense.

past perfect (noun)	pluperfect (noun)
a perfective tense used to express action completed in the past	a perfective tense used to express action completed in the past

past perfect (adjective)	pluperfect (adjective)
	more than perfect