Eilish is an Irish name of ancient Gaelic origin, derived from "Éile" meaning "sunny", often associated with females but suitable for males too. It was popular among medieval Irish nobility and bears historical significance through figures like Eibhlin Dhubh Ní Chonaill, a renowned 17th-century poet. Today, Eilish remains a charming choice for parents seeking to honor Irish heritage or bestow a unique name with rich history.