Origen del modismo 'a feather in one's cap'

The idiom a feather in one's cap is used to mean a personal achievement or honour to be proud of ('apuntarse un tanto' in Spanish). 
This idiom, according to Brewer's Dictionary of Phrase and Fable, comes from the custom, general in Asia and among the Native Americans, of adding a feather to the headgear for every enemy killed. The ancient Lycians and many others had a similar custom, just as the sportsman who kills the first woodcock puts a feather in his cap. At one time in Hungary the only person who could wear a feather was the one who had killed a Turk.

Glossary

- achievement - logro
- headgear - cualquier tocado para la cabeza (sombrero, gorra, gorro, etc.)
- ancient - antiguo,-a
- Lycians - habitantes de Lycia, antigua región en la costa sudoeste de Asia Menor.
- woodcock becada
- Hungary - Hungría
- Turk - turco