Brittle means hard but easy to break or snap. A thin cracker is brittle: it feels solid, but if you bend it even slightly, it shatters into pieces. Dry autumn leaves are brittle, crunching underfoot instead of bending like fresh green leaves do. Peanut brittle, the candy, gets its name because it's hard and breaks with a satisfying snap.

Things become brittle when they lack flexibility. Old rubber bands turn brittle and snap instead of stretching. Bones can become brittle with age, breaking more easily from falls that younger bones would handle. Cold makes many materials more brittle: a plastic toy that bends fine indoors might crack if you play with it outside on a freezing day.

The word also describes relationships or situations that seem fine on the surface but can't handle stress. A brittle friendship might seem normal until one disagreement causes it to fall apart completely. A brittle peace between countries might shatter at the first sign of trouble. When something is brittle, whether it's a material or a relationship, it lacks the strength to bend without breaking.