Preventive means something done to stop a problem before it happens. When you wash your hands before dinner, you're taking a preventive measure against getting sick. When a dentist cleans your teeth twice a year, that's preventive care designed to prevent cavities before they form.

Preventive actions are like putting up a fence at the edge of a cliff: much smarter than waiting to catch people who fall off. A bike helmet is preventive equipment that protects your head before an accident happens, not after.

Sometimes you'll see this word spelled “preventative,” which means exactly the same thing. Both are correct, though preventive is shorter and more common.

Preventive thinking shows up everywhere in smart planning. Fire drills are preventive practice for emergencies. Saving money is preventive planning against future financial trouble. When coaches teach proper stretching techniques, they're taking preventive steps against injuries. The key idea is always the same: act now to avoid problems later. It's like the old saying goes: an ounce of prevention is worth a pound of cure.