a.

1. 堅持不懈的；固執的
2. 持續的，持久的
   a time of high and persistent unemployment

   一個持續的高失業率的時期

3. 反覆的，不斷的
4. 【植】宿存的，不落的
5. 【動】持續生存的，終身保留的

adj.

1. persisting or having a tendency to persist.
2. continuing or recurring; prolonged.
3. Botany  & Zoology  (of a part of an animal or plant, such as a horn, leaf, etc.) remaining attached instead of falling off in the normal manner.