Vacuum technology

La bride à vide is the vacuum flange, and the first word is one of the cleanest false friends the language has. La bride is not a « bride ». It is a bridle: the headgear and reins by which a horse is held, and the two are in fact the same Germanic word, which French borrowed from Middle High German while English kept the form it had inherited. « Bride » in the wedding sense is a different word altogether and has no French descendant at all; the woman at the wedding is la mariée. From the strap, French generalised in the direction of anything that holds a part in place: a loop of thread on a garment, a tie in a piece of lace, and finally the collar of metal bolted round a pipe end, which is where this list finds it. English did not follow and reached instead for « flange », whose own origin is obscure. The figurative uses stayed with the horse on both sides of the Channel: lâcher la bride is to give free rein, and tenir la bride courte is to keep somebody on a short one.