Conventional means following the usual ways of doing things, sticking to established customs and methods rather than trying something new or unusual. A conventional approach is the standard, tried-and-true path that most people take.

In science class, a conventional experiment might use test tubes and microscopes, while an unconventional one might involve building robots or studying bacteria from your own kitchen. Conventional wisdom is what most people believe to be true, like “study hard to get good grades” or “look both ways before crossing the street.” These ideas have become conventional because they've worked well for many people over time.

The word isn't necessarily negative or positive. Sometimes conventional methods work perfectly well: there's a reason people conventionally use forks to eat spaghetti rather than their hands. Other times, progress requires someone to break from conventional thinking. The Wright brothers succeeded partly because they ignored conventional wisdom that said humans could never fly.

When someone calls you conventional, they might mean you prefer familiar, comfortable approaches. When they call you unconventional, they mean they notice you like to do things your own way.