A fixed amount of a commodity officially allowed to each person during a time of shortage, as in wartime. During the war, each family received a weekly ration of sugar and flour.
A fixed portion of food or provisions, especially for soldiers or sailors or for civilians during a shortage. The soldiers were given their daily rations before heading out on the mission.
An allotted or habitual amount of something, especially something regarded as one's share. I've had my ration of bad luck for one lifetime.