What is the meaning of Bristle?

A stiff or coarse hair, usually and especially on a nonhuman mammal.

A chaeta: an analogous filament on arthropods, annelids, or other animals.

The hairs or other filaments that make up a brush, broom, or similar item, typically made from plant cellulose, animal hairs, or synthetic polymers.

To rise or stand erect, like bristles.

To abound, to be covered with, or to have an abundance of, something, especially something jutting out.

To be on one's guard or raise one's defenses; to react with fear, suspicion, or distance.

To make (something) rise or stand erect, like bristles.

To cause (someone) to be on one's guard or raise one's defenses.

(Can we verify this sense?) To fix a bristle to.

Source: wiktionary.org