Literally: to have Damoclès’s sword above your head.

Origins: 5TH century BC, Damoclès was a courtesan at Denys the Old’s Syracuse tyrant court. Denys lived in a palace surrounded by a big ditch, with an army of guards. Damoclès, master jeweler, said to Denys, he was envious of his life. Annoyed, during a banquet, Denys made a proposition to Damoclès: to take his place for a whole day. At that moment, Damocles looked up and saw a sword above his head, only suspended by 1 horse’s hair, Damoclès realized, his life was very fragile, the sword could fall at any time. Denys meant to illustrate his life’s metaphor: a tyrant’s life.

During the 19th century, they talked about “une epèe de Damoclès” to describe a deplorable or dangerous situation. Meaning: to feel/be in a constant danger

Synonyms: Danger qui plane sur quelqu'un; la vie ne tient plus qu’à un fil.