lengthier , lengthiest
You use lengthy to describe an event or process which lasts for a long time.
The board members held a lengthy meeting to decide future policy.
董事会成员开了一次漫长的会议来决定未来的政策。
A lengthy report, article, book, or document contains a lot of speech, writing, or other material.
Friedman's lengthy report quoted an unnamed source.
弗里德曼冗长的报告引用了一个未指明出处的资料。