conga line

Wiktionary

1. n. A line of people dancing the conga.
2. n. Canada, figuratively A moving formation of snowplows and/or similar equipment, arranged in a diagonal line across a multilane highway, airport runway, or other roadway, such that the snow from the first vehicle is passed to the second, and then from the second to third, and so on, thereby clearing much or all of the route's width in a single pass.

GNU Webster's 1913

1. n. a line of persons dancing the conga{2}.
2. n. a line of persons similar to a conga line{1}. Sometimes used figuratively or humorously.

WordNet 3.0

1. n. a line of people in single file performing the conga dance