Avoir le bourdon

Literally: To have the bumblebee

Example: “Dimanche soir, j'ai toujours un peu le bourdon.” — On Sunday evenings, I always have the blues a bit.

English equivalent: To have the blues

Origin: French has at least four things called a bourdon, any of which could have produced this, which is exactly why it has never been settled. There is the bumblebee, a relative of the honeybee whose flight makes a low droning note — several going at once inside your head is a fair picture of dark thoughts. There is the musical bourdon, the sustained bass drone of a bagpipe or a vielle (hurdy-gurdy), as relentless as a worry you cannot put down. In printing, a bourdon is a word, a phrase, or a whole line accidentally dropped from a text, which would certainly ruin a typesetter's day. And a bourdon is a bell — a very large one with a very deep voice, rung for grave national occasions such as a defeat. Which of the four is the parent, nobody knows.