We don't have synonyms for manyfold yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are manifold, mangold and manyhood.
"1800 - The dramatic narrative of the close of Wolsey's life becomes manyfold more impressive from being told to the discrowned Queen Catherine - Lectures on English History and Tragic Poetry, as Illustrated by Shakspeare - Henry Reed"
"1772 - "I am right glad to hear of your manyfold successes" - The Lives of Those Eminent Antiquaries John Leland, Thomas Hearne, and Anthony ? Wood - (author?)"
"1800 - The dramatic narrative of the close of Wolsey's life becomes manyfold more impressive from being told to the discrowned Queen Catherine - Lectures on English History and Tragic Poetry, as Illustrated by Shakspeare - Henry Reed"
"1772 - "I am right glad to hear of your manyfold successes" - The Lives of Those Eminent Antiquaries John Leland, Thomas Hearne, and Anthony ? Wood - (author?)"