Condition means the state something is in, how it's working, or what shape it's physically in. When you check out a library book, the librarian might note its condition: is it crisp and new, or are the pages worn and the cover bent? When your parents buy a used car, they carefully examine its condition to see if the engine runs smoothly, if the tires have good tread, and whether the seats are torn.

The word also describes circumstances that must exist for something else to happen. A teacher might make homework completion a condition for going on the field trip. Your parents might set certain conditions before you can get a pet: you must feed it daily, clean its cage weekly, and save money for vet bills. These are requirements, things that must be met.

In science and medicine, condition can mean a health problem or illness, like a heart condition or skin condition. Scientists also talk about experimental conditions, meaning the specific circumstances under which they test something, such as temperature, pressure, or lighting.

When you condition your hair, you're treating it to improve its state. When athletes train, they're conditioning their bodies, getting them into peak shape. The word reminds us that nothing exists in isolation: everything has a state, and that state affects what happens next.