Undying (adjective)

1. Never dying or ceasing to exist.
2. Lasting forever.
3. Unwavering in the face of adversity or change.

Origin:

Late middle english: from un- "not" + dying.

Examples:

1. The love between them was undying.
2. The legend of King Arthur and his knights is an undying story.
3. The undying spirit of the warriors inspired the nation.
4. The memories of their childhood were undying in their minds.
5. The undying determination kept her going through the tough times.