adj.长期，（已持续）长时间的，为时甚久的
adv.长久

Longtime no see! How have you been?" - 好久不见！你过得怎么样？
We've been friends for a longtime, since childhood.
我们已经是多年的老朋友了，从小学就认识。
Longtime residents often feel more connected to their community.
长期居住的人通常对社区有更深的情感联系。
She's been with the company for a longtime, and she's very knowledgeable.
她在公司工作很久了，非常有经验。
The family has owned this house for longtime, passed down through generations.
这房子这家人已经拥有很长时间了，是祖传的财产。
Longtime smokers are at higher risk of developing lung cancer.
长期吸烟者患肺癌的风险更高。
It's been a longtime dream of mine to travel to Japan.
我梦想去日本旅行已经很久了。
Their friendship lasted a longtime despite the distance between them.
虽然相隔遥远，他们的友谊却维持了很长时间。
After a longtime search, he finally found the rare book he was looking for.
经过长时间的寻找，他终于找到了那本罕见的书。
He's been teaching here for longtime and is well-respected by his students.
他在这里教书多年，深受学生尊敬。