brad

n thin flat nail with no head or a very small head 角钉, 无头钉（无头或头很小的）.

boy, Boy Scout, boy-friend, boycott, boyfriend, boyhood, boyish, BP, BPC, BR, bra, brace, brace and bit hand, bracelet, bracing, bracken, bracket, brackets, brackish, bract, bradawl, brae, brag, braggadocio, braggart, brahmin, braid, braided, braiding, Braille, brain, brain fever, brain-child, brain-drain, brain-teaser, brainless, brainpower, brains trust (US brain trust), brainstorm, brainstorming,