marsh melon
noun
A cultivar of melon, especially the canteloupe, Cucumis melo subsp. agrestis var. cantalupensis, and another melon found chiefly in India, Cucumis melo subsp. melo var. mormordica, whose ovoid to cylindrical fruit have white or pale orange flesh that is fairly low in sugar.
Origin
Early 19th century; earliest use found in British Press.