1) Becoming unclean 2) Befouling 3) Change of state 4) Dirtying 5) Dirtying up 6) Soilure 7) The act of soiling something 8) The act of something Found on https://www.crosswordclues.com/clue/soiling
A build-up of soil particles and similar materials that cling to carpet fibers. Thorough and frequent vacuuming is the key. If vacuuming is not enough, its time for a professional cleaning. Found on https://www.encyclo.co.uk/local/22737