Be honest, list any skills you gained from it and explain why you are now ready to re-enter the workforce. If you took time out to care for a sick relative, you could say that you gained skills in co-ordinating care appointments and increased patience. They are now recovered and will not need care in the future and you are able to commit completely to a new job.
Explaining why you are now able to commit completely is important. An employer may be worried that you will require a lot of time off or that you will not stay in your job.