compression

Everyday

1. Compression is pressing or squeezing something so it takes up less space. tree →
2. Compression is making a computer file smaller so it is quicker to send. tree →
3. In first aid, compressions are pushes on the chest in CPR. tree →

In the lessons

In science, gases can be compressed but solids hardly at all; springs show compression when squashed. In first aid lessons chest compressions help keep blood moving when the heart stops. In computing, compression makes photos and videos smaller. Phrases: chest compressions, file compression.

Examples

• Squeezing the spring is compression. tree →
• Air can be squashed by compression, but water hardly at all. tree →
• Chest compressions are part of CPR. tree →
• File compression makes pictures quicker to send. tree →
• The bridge must stand up to compression and tension. tree →
• A compression bandage helped my swollen ankle. tree →

Note

Verb: compress. Opposite in forces: tension (pulling, stretching). Mostly uncountable, but «chest compressions» is plural.