Susceptible means easily affected by or vulnerable to something. When doctors say that young children are susceptible to colds, they mean kids catch them more easily than adults do. A plant susceptible to frost will be damaged by cold weather that hardier plants can handle.

The word often appears with “to”: you might be susceptible to peer pressure, meaning you're easily influenced by what your friends think. Someone susceptible to flattery believes compliments too quickly, even insincere ones. A computer system susceptible to viruses needs better protection.

Being susceptible isn't always negative. You could be susceptible to the charm of a good story, meaning you're easily drawn into books. An artist might be susceptible to inspiration from nature.

The key idea is openness or vulnerability to outside influence. Think of it like a door that's easier to open than others: when you're susceptible to something, that thing has an easier time affecting you. A student who gets enough sleep and eats well becomes less susceptible to illness. Understanding what you're susceptible to helps you protect yourself from harm or, in positive cases, recognize what moves and inspires you.