To revert all features ..
drush fra -y drush cc all
To revert a specific feature..
drush fr -y feature drush cc all
If a feature has been overridden, it can be reverted. This means that the version in the database is destroyed and the version defined in code, in your feature, is used.
If you're deploying a feature to one of you servers you would ..
git pull drush fra -y drush cc all
To update your feature ..
drush fu -y feature drush cc all
Updating an overridden feature will ensure that the version of the feature defined in code is made to match the version stored in the database.
A feature is overridden when a user uses the UI to make configuration changes. These changes are stored in the database, and override what is stored in code.