Prendre la poudre d'escampette

Literally: To take the escampette powder

Example: “En entendant la sirène, les voleurs ont pris la poudre d'escampette.” — Hearing the siren, the thieves hightailed it out of there.

English equivalent: To hightail it

Origin: There is no such plant as escampette. The word is a diminutive of escampe, which in the 16th century meant flight, itself from the verb escamper, a coarse synonym of fuir (to flee) that appears in the 14th century. Escampette survives today in nothing but this one phrase, which dates from the 17th century. The poudre is less certain: it may be the exploding kind that sets someone running, but more likely it is simply the dust of the road that a man in flight was pictured kicking up behind him.