General:
* Durable: Emphasizes strength and resilience.
* Enduring: Implies something that continues for a long time.
* Permanent: Suggests something that will never end.
* Continuing: Highlights the ongoing nature of something.
* Persistent: Implies something that continues despite difficulties.
* Sustained: Refers to something that is maintained over time.
More specific:
* Eternal: Suggests something that lasts forever.
* Everlasting: Similar to "eternal."
* Unending: Emphasizes the lack of a limit.
* Chronic: Used for conditions that persist over a long period.
* Protracted: Implies something that lasts for a longer time than expected.
* Indefinite: Suggests that the duration is unknown.
Informal:
* Long-lasting: A simple and straightforward synonym.
* Long-term: Used to describe something that extends over a long period.
The best synonym for "lasting" will depend on the specific context of your writing. Consider the meaning you want to convey and choose the word that best fits your needs.