Packaging technology

The eighth entry is o fecho resistente a crianças, and the English compound that looks obvious for it is the one the trade refuses to print. « -proof » is a live suffix: hang it on a noun and the word swears that the thing named cannot get through. « Waterproof » keeps water out, « soundproof » keeps sound out, « bulletproof » stops the bullet, and « foolproof » is safe even in the hands of a fool. It builds verbs too — a parent « childproofs » a flat, an engineer « future-proofs » a system. Every one of these compounds names a danger and then dismisses it outright, and that absolute is the whole force of the suffix. It is also why no specification anywhere calls the cap on a medicine bottle « childproof ». Nothing survives a determined four-year-old; what the design offers is resistance, measured against real children and a clock. So resistente a crianças is « child-resistant », and « childproof », common enough in a newspaper, is a claim the industry declines to make.