identity

Everyday

1. Who someone is: The police found out the thief's identity. tree →
2. The things that make a person or group who they are, like their name, culture and beliefs: our school's identity. tree →
3. Being exactly the same: an identity of interests. tree →
4. (maths) An equation that is true for every number, like a + b = b + a. tree →

In the lessons

In everyday life you show an identity card or ID; in safety lessons you keep your identity safe online and never share passwords; in stories heroes have a secret identity. Phrases: «identity card», «secret identity», «mistaken identity», «identity theft».

Examples

• The superhero kept his identity secret. tree →
• You need proof of identity to open a bank account. tree →
• Never share your passwords — someone could steal your identity. tree →
• Music is part of our town's identity. tree →
• It was a case of mistaken identity. tree →
• In maths, 2 × (a + b) = 2a + 2b is an identity because it is always true. tree →
• Then send him to my palace at Athens bearing these tokens of his identity." tree →

Note

Plural «identities» (y → ies). Short form: ID. Verb: identify; adjective: identical (exactly alike). In maths, an identity holds for every value, while an equation like x + 2 = 5 holds only for one value.