marl UK /mɑːl/US /mɑɹl/noun 2verb 2forms 3 noun2 •A mixed earthy substance, consisting of carbonate of lime, clay, and possibly sand, in very variable proportions, and accordingly designated as calcareous, clayey, or sandy.... uneasie steps / Over the burning Marle, not like those steps / On Heavens Azure... — 1667 •(Australia) A species of bandicoot, Perameles myosurus, of southern Western Australia. verb2 •To cover (the ground) with marl (noun sense). •To cover, as part of a rope, with marline, marking a peculiar hitch at each turn to prevent unwinding. formsmarled · marling · marls