a.

1. 一致的，协调的
   They seem to have no coherent plan for saving the company.

   他们似乎没有一个协调一致的挽救公司的计划。

2. （话语等）条理清楚的，连贯的
   a coherent argument

   前后一致的论点

3. 有粘性的；粘合在一起的
4. 【物】相干的，相参的

adj.

1. (of an argument or theory) logical and consistent.
   ▸able to speak clearly and logically.
2. holding together to form a whole.
3. Physics  (of waves) having a constant phase relationship.