thinner

Everyday

1. Less thick: having a smaller distance from one side to the other, like a thinner slice of bread or a thinner book. tree →
2. Less fat: a person or animal with less fat on the body. tree →
3. Runnier and more watery, like thinner soup or thinner paint. tree →
4. Less crowded or full, as in the crowd grew thinner, or the air is thinner on a high mountain. tree →
5. As a noun, thinner is a liquid used to make paint runnier or to clean brushes. tree →

In the lessons

In maths, "thinner" compares sizes: a 2 mm sheet is thinner than a 5 mm sheet, by 3 mm. In science, air gets thinner (less oxygen in each breath) high up on mountains, and ice that is thinner can crack, so it is dangerous to walk on. In cooking, adding water makes a sauce thinner. Paint thinner is a chemical that is poisonous and catches fire easily — only adults should use it. Phrases: "thinner than", "wear thinner", "my patience is wearing thin".

Examples

• This slice of cake is thinner than that one. tree →
• The ice is thinner near the middle of the pond, so stay off it. tree →
• Add a little milk to make the batter thinner. tree →
• The air is thinner at the top of the mountain. tree →
• After the race, the crowd grew thinner. tree →
• A sheet of paper is thinner than a piece of card. tree →
• Dad cleaned his brushes with paint thinner in the garage. tree →
• The old dog looks thinner since he has been ill. tree →
• Luckily, just at that place the trees grew thinner, and he could see a small farmhouse a little way off. tree →

Note

Thin doubles the n: thinner, thinnest. Opposite: thicker (for size or liquids), fatter (for bodies). Calling someone fat or thin can hurt; talk about bodies kindly. In maths, "A is 3 mm thinner than B" means subtract 3 from B's thickness. Paint thinner is not a food or drink and must be kept away from children.