Other forms: pipelines
A pipeline is a line of pipes carrying liquid, or work waiting ahead. A gas pipeline, in the pipeline, the sales pipeline.
In the pipeline is the figurative use and means already begun but not yet arrived, which is why it appears in every progress report. A real one moves oil and gas across continents more cheaply than any ship.
1nounpipelineA line of pipes carrying liquid, or work waiting ahead.
“The company has several new products in the pipeline for next year.”
pipeline is a line.
Pipe plus line, from the nineteenth-century oil industry, where the first long lines were laid.
From pipe + line.
Etymology from Wiktionary, CC BY-SA