a long tubular conduit or series of pipes, often underground, with pumps and valves for flow control, used to transport crude oil, natural gas, water, etc., esp. over great distances.

a route, channel, or process along which something passes or is provided at a steady rate; means, system, or flow of supply or supplies

Freighters and cargo planes are a pipeline for overseas goods.

a channel of information, esp. one that is direct, privileged, or confidential; inside source; reliable contact.

to convey by or as if by pipeline

to pipeline oil from the far north to ice-free ports; to pipeline graduates into the top jobs.

in the pipeline

Informal . in the process of being developed, provided, or completed; in the works; under way.

Government Informal . (of funds) authorized but not spent.