to untie (a string, etc.), to open (a book), to delve into, to unravel (a mystery, history)

💡 Nuance & Usage: Often used metaphorically for 'unraveling' or 'delving into' complex subjects like history, mysteries, or ancient texts, rather than literally untying a physical string. It implies careful examination and understanding. (比喩的に、歴史や謎、古い書物などを「解き明かす」「深く調べる」という文脈で使われます。物理的な紐を解くよりも、複雑な物事を丁寧に調べて理解するという意味合いが強いです。)