pluperfect vs perfect tense

pluperfect and perfect tense both are nouns.

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

As nouns, perfect tense is a hypernym of pluperfect; that is, perfect tense is a word with a broader meaning than pluperfect:

pluperfect: a perfective tense used to express action completed in the past
perfect tense: a tense of verbs used in describing action that has been completed (sometimes regarded as perfective aspect)

Other hypernyms of pluperfect include perfect, perfective, perfective tense.

pluperfect (noun)	perfect tense (noun)
a perfective tense used to express action completed in the past	a tense of verbs used in describing action that has been completed (sometimes regarded as perfective aspect)

pluperfect (adjective)	perfect tense (adjective)
more than perfect