also: ゴルディオスのむすびめ
expression, noun
Gordian knot
Refers to the legendary knot tied by Gordius, used metaphorically for an intricate problem solved by bold action.
その問題はまさにゴルディアスの結び目だったが、彼は一気に解決した。
That problem was truly a Gordian knot, but he solved it in one stroke.
難問 is a general term for a difficult problem, while ゴルディアスの結び目 specifically implies a seemingly intractable problem that requires an unconventional solution.
From the Greek legend of Gordius, whose intricate knot was cut by Alexander the Great. The Japanese expression is a direct borrowing of the Western phrase.