1. （常指埋于地下的石油或燃气）管道，管线
A pipeline is a large pipe which is used for carrying oil or gas over a long distance, often underground.
e.g. A consortium plans to build a natural-gas pipeline from Russia to supply eastern Germany.
一家财团计划建造一条从俄罗斯向德国东部输送天然气的管道。
2. 在筹备中；在进行中
If something is in the pipeline, it has already been planned or begun.
e.g. Already in the pipeline is a 2.9 per cent pay increase for teachers.
教师的工资将上调2.9%，此事正在运作中。
noun
1. a pipe used to transport liquids or gases
e.g. a pipeline runs from the wells to the seaport
Synonym: line
2. gossip spread by spoken communication
e.g. the news of their affair was spread by word of mouth
Synonym: grapevineword of mouth