deform

Everyday

1. To change the normal shape of something, often by bending, squashing or stretching it: «Heat deformed the plastic». tree →
2. (of a body part) To grow or be made into an unusual shape, for example by illness or injury. tree →

In the lessons

In science lessons on forces and materials, pupils test how springs and modelling clay deform when pushed or pulled; elastic materials go back to their shape, plastic ones stay deformed. In geography, rock layers deform into folds when continents push together, forming mountains. Phrases: «deform under pressure», «permanently deformed», «deformed by heat».

Examples

• The plastic bottle deformed in the hot car. tree →
• Squeezing the ball deforms it, but it springs back. tree →
• The bridge was built not to deform under heavy lorries. tree →
• Rocks deform into folds when plates push together. tree →
• The clay deforms easily when you press it. tree →
• Too much weight will deform the shelf. tree →

Note

Noun: «deformation» (in science) and «deformity» (an unusual body shape). Calling a person «deformed» is hurtful; say they have a disability or a particular condition. In science, «elastic deformation» goes back; «plastic deformation» stays.