convention

Everyday

1. The usual or accepted way of doing something; a custom or rule people follow. tree →
2. A large meeting of people with the same interest or job (a comic convention). tree →
3. An official agreement between countries (the Geneva Convention). tree →
4. (maths, writing) A standard rule everyone agrees to use, such as writing numbers left to right. tree →

In the lessons

In maths: conventions such as the order of operations (BODMAS/BIDMAS/PEMDAS) and labelling axes x and y. In English: writing conventions like capital letters and full stops. In everyday life: comic conventions, conventions of politeness. Phrases: by convention, break with convention.

Examples

• By convention, we write the x-axis across the page. tree →
• Spelling and punctuation are writing conventions. tree →
• We dressed up for the comic convention. tree →
• Shaking hands is a convention in many countries. tree →
• The Geneva Convention protects prisoners of war. tree →
• The writer broke with convention and used no capital letters. tree →
• The possibility of the introduction of an archaic formula which had become a convention of folk-telling cannot be left out of account. tree →

Note

Adjective: conventional (usual, ordinary). In maths, conventions are agreed rules, not proven facts; following them means everyone gets the same answer.