A British railway term for the Metropolitan line, the oldest underground railway route in London. Railway workers and commuters alike use this shorthand to differentiate it from the deep-level tube lines, as the Met operates with larger subsurface rolling stock and shares characteristics with mainline commuter rail.
Heard on the job
We had a signal failure on the Met this morning, so they routed everything over the Jubilee.
Insider tip
Because it uses mainline-sized trains, track workers treat the Met more like a traditional railroad than a deep tube line.