marasmus (n.)

"wasting away of the body," 1650s, Modern Latin, from Greek marasmos "a wasting away, withering, decay," from marainein "to quench, weaken, wither," from PIE root *mer- "to rub away, harm," but Beekes has doubts about this. "The term is usually restricted to cases in which the cause of the wasting is obscure" [Century Dictionary]. Maras (n.), evidently in the same sense, is attested from mid-15c. Related: Marasmic.