brad

noun

1. A thin, small nail, with a slight projection at the top on one side instead of a head, or occasionally with a small domed head, similar to that of an escutcheon pin.

   “Into the middle arch of each desk silver-headed brads had been hammered to form a lion, a bear, a ram, a dove, and in the midst a flaming torch.”

2. (US)A paper fastener, a fastening device formed of thin, soft metal, such as shim brass, with a round head and a flat, split shank, which is spread after insertion in a hole in a stack of pages, in much the same way as a cotter pin or a split rivet.
3. A binary radian.

verb

1. (transitive)To attach using a brad.
2. (transitive)To upset the end of a rod inserted in a hole so as to prevent it from being pulled out, as when riveting.