reduce

What a makeover this verb has had: in late medieval French and English, it was basically a rescue operation, a way to bring something back where it belonged. The Latin pieces are plain as bricks — re- for “back” and ducere for “lead” — the same leading-downroad family that gave English words like deduce, induct, conduct, and even introduce. For centuries, English used reduce in kindly ways, like bringing a sinner back to virtue or a sick person back to health, which sounds almost the opposite of what it means in a calorie-counting app. Then the harsher senses took over: lowering rank, subduing a town, thinning a sauce, simplifying an equation. So when you reduce something, you’re still doing that old Roman action of leading it back — only now the destination is smaller, simpler, or more manageable, as if the word has been given a ruler and a pair of scissors at the same time.