a short, stiff, coarse hair, as on the back of swine.-a stiff, sharp, roundish hair.-to erect the bristles of; to cause to stand up, as the bristles of an angry hog; -- sometimes with up.-to fix a bristle to; as, to bristle a thread.-to rise or stand erect, like bristles.-to appear as if covered with bristles; to have standing, thick and erect, like bristles.-to show defiance or indignation.