pluperfect
noun(also past perfect, the past perfect tense)
[singular] (the form of a verb that expresses an action completed before a particular point in the past, formed in English with had and the past participle 过去完成时；过去完成式 Word Originlate 15th cent.: from modern Latin plusperfectum, from Latin (tempus praeteritum) plus quam perfectum ‘(past tense) more than perfect’.