IPA: /ˌɔːtəʊbaɪˈɒɡrəfə/
KK: /ɔːˌtɒbɪˈɒɪɡrəfə/
A person who writes about their own life story.
The famous autobiographer shared her experiences in a bestselling book.
Autobiographer → It is formed from "auto-" (meaning self) and "biographer" (from "bio-" meaning life and "graph" meaning to write). The word refers to someone who writes about their own life.
Think of 'self' ('auto-') writing about their own 'life' ('bio-') — that's what an autobiographer does.