прошедшая жизнь is a combination that is seldom used to describe the span of life that has passed already. "Past" is usually translated as «прошедший» when you are talking about grammatical tense (прошедшее время, настоящее время, будущее время). Your previous incarnation (metaphorical or real, if you believe in reincarnation) is «прошлая» жизнь.
What is the Anglo-Phonetic Spelling of "Life" in Russian ? I do appreciate the word bank for those of us that do not have the Capability of Switching to the Cyrillic Alphabet. I have tried jizn', djizn', jeezn', jhizn' and more..Thank You for your website. I am brushing up on Six Languages and am studying 7 More ! Blessings Always !