expression, adverb
literally; self-explanatorily
Used to emphasize that something is exactly as the words say, with no hidden meaning or interpretation needed. Often appears as a set phrase.
読んで字のごとく、彼は本当に正直者だ。
Literally, he is truly an honest person.
この料理は読んで字のごとく、見た目も味も素晴らしい。
This dish is, literally, wonderful both in appearance and taste.
文字通り also means 'literally' but is more common and neutral. 読んで字のごとく is a more emphatic, idiomatic expression.
A set phrase composed of 読んで (reading) + 字 (character/word) + の + ごとく (like/as). Literally 'as if reading the characters', meaning exactly as written.