"an article plaited or woven of more or less coarse natural materials (rushes, straw, twine, etc.) used as bedding, floor-coverings, etc.," Old English matte, from Late Latin matta "mat made of rushes" (4c.), probably from Punic or Phoenician matta (compare Hebrew mittah "bed, couch").
Meaning "tangled mass; anything closely set, dense, and thick" is from 1835. Meaning "thin, flat article to be placed under a dish, plate, etc. to protect the table" is by 1800. That of "piece of padded flooring used in gymnastics or wrestling" is attested from 1892; hence figurative phrase go to the mat "do battle" (1910). The Latin word also is the source of German Matte, matze; Dutch mat, Italian matta. French natte "mat, matting" is from Late Latin secondary form natta (compare napkin).