1To complain of, bemoan; to lament over. In early use: †to mutter, mumble (obsolete).
2rare Of a baby: to coo, to gurgle.
Mid 16th century. Probably from Old French mormeler, Old French (Picardy) murmillier to murmur from a Germanic form cognate with Old High German murmulōn; compare also Middle High German, German murmeln.