cohort

Everyday

1. A cohort is a group of people who have something in common, such as the same age or starting school together. tree →
2. (formal) A cohort is a group of people studied together in research. tree →
3. (history) A cohort was a unit of soldiers in the Roman army, of about 480 men. tree →
4. (informal) A cohort can mean a supporter or companion of someone. tree →

In the lessons

In schools and formal reports, «this year's cohort» means all the pupils in one year group. In history lessons, a Roman legion was made of cohorts. In science, a cohort study follows the same people over time. Phrases: year cohort, cohort study, a Roman cohort.

Examples

• This year's cohort of pupils did well in the tests. (formal) tree →
• A Roman cohort had six centuries of soldiers. tree →
• The study followed a cohort of 800 children. tree →
• The new cohort of nurses started training today. tree →
• The cohort has 90 pupils in 3 classes, so 30 in each. tree →
• The villain arrived with his cohorts. (informal) tree →

Note

Countable noun; formal. In the Roman army, a legion had 10 cohorts. The informal sense «companions» is common but some people dislike it. In maths, a cohort split into equal classes is a division problem.