also: ゴルディオスのむすびめ
Gordian knot
Refers to the legendary knot tied by Gordius, used metaphorically for an intricate problem solved by bold action.
That problem was truly a Gordian knot, but he solved it in one stroke.
Alternate form using ゴルディオス; both are encountered.
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.