Ageless means never seeming to grow old. An ageless beauty, an ageless design, ageless appeal.
Of a person it is a compliment about appearance, and of a design or a story it means it has not dated. It is one of the few compliments that can be paid to a building and a face in the same words.
1adjectiveagelessNever seeming to grow old.
“My grandmother seems ageless; she looks the same as she did twenty years ago.”
ageless is a quality.
From age + -less.
Etymology from Wiktionary, CC BY-SA