A jar is a container, usually made of glass or ceramic, with a wide mouth and no spout. Jars hold all kinds of things: pickles, jam, honey, flour, buttons, or coins. Unlike bottles, which have narrow necks for pouring, jars have openings big enough to reach your hand inside. Mason jars, named after inventor John Landis Mason, became famous for preserving food because their metal lids could seal tightly, keeping air out and freshness in.

The word also means to shake or jolt something unpleasantly. A rough car ride might jar you in your seat. A sudden loud noise can jar your nerves. When something jars you, it's like being bumped hard enough to rattle your teeth. Writers use this meaning to describe experiences that disturb or shock: “The harsh criticism jarred him” or “The news jarred her out of her daydream.”

Sometimes things jar with each other, meaning they clash or don't fit together well. Bright orange curtains might jar with purple walls, creating an unpleasant combination that feels wrong to look at.