birthmark

n unusual coloured mark on a person's skin at birth 胎记; 胎痣.

bird of passage, bird of prey, bird sanctuary, bird-bath, bird-song, bird-table, bird-watcher, birdbrained, birdcage wire, birdie, birdlime (also lime), birds, birdseed, biretta, Birmingham, birth, birth certificate, birth rate, birth-control, birthday, birthplace, birthrate, birthright, biscuit, bisexual, bisexuality, bishop, bishopric, bismuth, bison, bistro, bit, bit by bit, bit part, bitch, bitchiness, bitchy, bite, biting, bitingly,