a Gordian knot

(formal)

a difficult problem

Usage notes: In an old story, King Gordius of Phrygia tied a complicated knot which no one could make loose, until Alexander the Great cut it with his sword.

Homelessness in the inner cities has become a real Gordian knot.

Common Names:

Name	Pronounced	Usage
Sheree	SHER-ee, shə-REE	English
Stanimir	-	Bulgarian, Russian, Serbian, Medieval Slavic
'Adoniyah	-	Biblical Hebrew
Robin	RAH-bin (English)	English, Dutch, Swedish
Djehutimesu	-	Ancient Egyptian
Karoline	kah-ro-LEE-nə (German)	German, Danish, Norwegian