Spiky (adjective)

1. Having or covered with spikes or sharp points.
2. Having a sharp, sudden, and short-lived effect.

Origin:

From the word "spike" which means a point or long thin piece of something.

Examples:

1. The hedgehog's spiky fur makes it difficult for predators to grab it.
2. The cactus plant has spiky needles all over its body.
3. The spiky hairstyle was popular in the 80s.
4. The stock market had a spiky behavior, with sudden drops and sudden rises.
5. The spiky graph showed the fluctuations in temperature throughout the day.