also featherweight, "lightest weight allowable by rules," 1812 (earlier as simply feather, 1760), from feather (n.) + weight (n.). Originally in horse-racing; boxing use as a specific weight class dates from 1889.
1. The feather must be removed with a straight, firm pull.
2. She and my mother were birds of a feather.
3. I taped the base of the feather onto the velvet.
4. Harry'sappointment to this important post was a feather in his cap.
5. Winning the gold medal was a feather in his cap.