If a watch, a phone, or a machine is shockproof, it has been built so that a drop or a knock is much less likely to break it. The shock here is a hard hit, not a scary surprise. You see the word on boxes and in ads. Though actually shockproof does not mean “nothing can ever break this.” It means it can take a normal bump better than a fragile one. A shockproof watch can still smash if you throw it hard at a wall. The same -proof ending appears in waterproof: “protected against ___.” You may also meet a verb, to shockproof something, meaning to make it able to take a hit; the label on the box is still the adjective.