elective
A class or activity you choose instead of being required.
An elective is a class you choose to take because it interests you, rather than one you're required to take. While everyone in middle school might have to take math, science, and English, you get to pick your electives: maybe art, woodworking, coding, drama, or Spanish.
In school, your core classes are decided for you, but electives let you explore subjects that match your interests and talents. One student might elect to take band while another chooses creative writing. These choices help you discover what you enjoy and might even point toward future careers.
Outside of school, elective describes anything you choose to do rather than something required. Doctors perform elective surgery when patients choose to have an operation that isn't medically urgent, like getting wisdom teeth removed before they cause problems.
The word can also work as an adjective. An elective course is one you select yourself. An elective procedure is one you opt into. The key idea is always choice: you're making a decision rather than following a requirement. This freedom to choose makes electives exciting because you're studying something you genuinely want to learn about.