A freshener is something that makes the air smell cleaner or more pleasant. The most common kind you'll encounter is an air freshener, those small devices or sprays people use in bathrooms, cars, or rooms to cover up bad odors or add a nice scent. You might see a little cardboard tree hanging from a car's rearview mirror (that's an air freshener), or notice someone spraying something after cooking fish in the kitchen.

Air fresheners work in different ways. Some release scent continuously from a small container plugged into an outlet. Others are sprays you use whenever needed. Some are just scented pieces of gel or paper that slowly release fragrance over time.

The word freshener can describe anything that refreshes or renews something. A breath freshener is a mint or spray that makes your breath smell better. Some people use fabric fresheners on curtains or furniture to make them smell clean without washing them. The basic idea is always the same: taking something stale, musty, or unpleasant and making it fresh again. Think of it like the reset button for smells, though it's worth noting that fresheners can cover up odors rather than actually removing what causes them.