What does "bristle" mean?

Additional senses

1. 2.To erect the bristles of; to cause to stand up, as the bristles of an angry hog; -- sometimes with up. Now for the bare-picked bone of majesty Doth dogged war bristle his angry crest. Shak. Boy, bristle thy courage up. Shak.
2. 3.To fix a bristle to; as, to bristle a thread.
3. 4.To rise or stand erect, like bristles. His hair did bristle upon his head. Sir W. Scott.
4. 5.To appear as if covered with bristles; to have standing, thick and erect, like bristles. The hill of La Haye Sainte bristling with ten thousand bayonets. Thackeray. Ports bristling with thousands of masts. Macaulay.
5. 6.To show deflance or indignation. To bristle up, to show anger or deflance.