thump mat
 n.— «‘Thump mats,” as they became known, were handmade by sailors to muffle the sound of the pulleys hitting the wooden deck, for the benefit of those trying to sleep below deck.» —“Need rope? Knot a problem for Barry” by Jodie van de Wetering ABC (Wide Bay, Queensland, Australia) June 15, 2005. (source: Double-Tongued Dictionary)

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