fog

Everyday

1. A thick cloud of tiny water drops near the ground that makes it hard to see. tree →
2. A state of confusion: "in a fog". tree →
3. As a verb, to become covered with tiny drops of water so you cannot see through it: "My glasses fogged up." tree →

In the lessons

In weather and science lessons, fog forms when moist air cools near the ground; it is really a cloud at ground level. In safety, fog makes roads and the sea dangerous, so drivers slow down and use fog lights, and walkers wear bright clothes. Phrases: thick fog, fog lights, fog horn, fog up, in a fog.

Examples

• The fog was so thick we couldn't see the house. tree →
• Drivers must slow down in fog. tree →
• The ship sounded its foghorn. tree →
• My glasses fogged up when I came inside. tree →
• The bathroom mirror fogs up after a shower. tree →
• Wear bright clothes on foggy mornings. tree →
• "If the fog would only clear away!" he said. tree →

Note

Mostly uncountable: "thick fog"; the adjective is "foggy". Double g in "fogged, fogging". Mist is thinner than fog. Science: steam on a cold mirror is water vapour condensing back into tiny drops.