[ ˌpɛrɪpɪ'tʌɪə , -'ti:ə ]
■ noun formal a sudden reversal of fortune or change in circumstances.
Origin
C16: from Gk ~ 'sudden change', from peri- 'around' + the stem of piptein 'to fall'.
PERIPETEIA
Meaning of PERIPETEIA in English
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004