the dogs bark, but the caravan goes on, sticks and stones may break my bones, but words will never hurt me (let people say what they will)

speed of light (the speed of electromagnetic radiation in a vacuum or in a substance)

mad cow disease

(idiomatic) to cost an arm and a leg: to cost too much, to be very expensive

against the clock / time trial

cash cow (something that generates free cash flow)

dulce de leche (sweat dairy spread)

Vulgar Latin

flour mite (Acarus siro)

(engraving) lettered. "Épreuve, gravure après la lettre": a print made after the caption is added (lettered proof)