* Retrained is the past tense and past participle of the verb "to retrain." It means to have been trained again or to have undergone further training.
* Retraining is the present participle of the verb "to retrain." It can be used as a noun or adjective, meaning the act or process of training someone again or the process of acquiring new skills.
Examples:
* Retrained: "She was retrained as a web developer after losing her job."
* Retraining: "He is currently undergoing retraining to become a chef."
* Retraining: "The company offered retraining programs to its employees."