chugging

verb

1. (form-of, gerund, participle, present)present participle and gerund of chug

noun

1. The sound of something that chugs.

   “There was a Thompson class "B1" in Birmingham New Street, and an ex-Great Eastern class "B12/3" in the Midland station at Leicester, where the contented chugging of its Westinghouse air-compressor struck an exotic note.”

   “From the nearby rail yards came clangings, groanings, chuggings.”