A self-educated person mainly taught themselves — by reading, trying, and thinking — rather than sitting in a classroom and being taught. People often say it with respect, as if pointing to a long, quiet effort. It does not always mean “never went to school.” It means the real learning was their own work. The word is a little formal, the sort you meet in a life story. In everyday talk, people more often say “I taught myself” or “I’m self-taught.” Self-taught is the close twin; self-educated sounds a bit more like a biography. Though actually, nobody learns in a sealed box — we all pick things up from other people — but the word is about the path, not a pure, lonely fact.