"restriction to limited allotments," 1865, verbal noun from ration (v.). Specifically of restrictions during wartime from 1917, in reference to conditions in England during the late stages of World War I.
Entries linking to rationing
ration v.
"put (someone) on a fixed allowance," 1859, from ration (n.); sense of "divide into rations, apportion in fixed amounts" is from 1870. Related: Rationed; rationing. Middle English racionable (late 15c.) meant "reasonable."