lasting
Continuing for a long time, not just for a short while.
Lasting means continuing for a long time or having effects that endure. When you build a lasting friendship, you create a bond that stays strong through years and different stages of life, remaining close even as circumstances change.
Some things are designed to be lasting. A well-made pair of boots might give you lasting wear, serving you reliably for years. A powerful book can make a lasting impression on your mind, shaping how you think long after you close it. When you learn something deeply rather than memorizing it for a test, you gain lasting knowledge that stays useful.
The opposite of lasting is temporary or fleeting. A sunburn might hurt intensely but heal in days, while a scar can be lasting. A fad might dominate the playground for weeks before everyone forgets it, but a truly good game has lasting appeal that keeps people playing it for generations.
Notice that lasting doesn't always mean forever. It simply means something persists beyond what's typical or expected. When someone achieves lasting success, they maintain their accomplishments over time through continued effort and adaptability, going well beyond a single good year.