marl
Concise Oxford English Dictionary © 2008 Oxford University Press:
marl1
▶noun an unconsolidated sedimentary rock or soil consisting of clay and lime, formerly used as fertilizer. ▶verb apply marl to.
– derivatives
marly adjective.
marly adjective.
– origin ME: from OFr. marle, from med. L. margila, from L. marga, of Celtic origin.
Concise Oxford English Dictionary © 2008 Oxford University Press:
marl2
▶noun a mottled yarn or fabric.
– derivatives
marled adjective.
marled adjective.
– origin C19: shortening of marbled.
'marl' also found in these Oxford entries:

