prone

A person who's prone to something has a tendency or habit that they can't help. For example, "He's prone to getting headaches when it's humid outside."

When we talk about being prone to something, it usually means that it happens often because of some underlying reason or tendency in the person. It might be related to their behavior, like someone who's prone to overspending on luxury items. They might have a habit of doing this and can't seem to change it no matter how hard they try. It could also be related to their health - for instance, if you're prone to getting sick during the winter months because your immune system weakens in cold weather.

It's worth noting that "prone" can also mean lying down or face-down when describing a position, like when you see people prone on the ground after an accident. This is more of a physical meaning and not related to the other uses of the word.