Definition of perfect noun from the Oxford Advanced Learner's Dictionary

BrE BrE//ˈpɜːfɪkt//
 
; NAmE NAmE//ˈpɜːrfɪkt//
 
the perfect (also the perfect tense) [singular] (grammar) the form of a verb that expresses actions completed by the present or a particular point in the past or future, formed in English with part of the verb have and the past participle of the main verb see also future perfect, past perfect, present perfect See related entries: Grammar
Word Origin Middle English: from Old French perfet, from Latin perfectus ‘completed’, from the verb perficere, from per- ‘through, completely’ + facere ‘do’.
See the Oxford Advanced American Dictionary entry: perfect