1. Short, stiff hair, fiber, etc.: Sam's face was covered with bristles which he brushed with the bristles of a brush.
2. Short stiff hairs or hairlike structures on animals or plants; or a mass of short stiff hairs growing; especially, on a hog's back or on a man's face: The fancy kitchen supply store sold brushes made of hog’s bristle.

The man's wife would not kiss him because the bristles on his face irritated the skin of her mouth and face.

1. To stand on end and to become stiff: The hair on the dog's neck bristled as he barked at something which was moving outside.

Electricity can make a person's hair bristle and become stiff.

2. To cause the hair on the back of an animal to go up or to rise: The cat bristled when it saw a dog coming toward it.
3. To react in an angry or offended manner: The author of the book bristled when someone suggested that he plagiarized some of the content.

The actress bristled at the criticism presented in newspaper articles.

4. To abound with sharp stiff thorns or sticks: The path bristled with the thorns of many bushes which caught onto the clothes of the people as they went for their walk.