The period of a person’s immaturity or youth.Enlightenment is man's emergence from his self-imposed nonage....
But Strawson does not give a sufficiently illuminating account of the general capacities that are absent or compromised in such conditions as nonage or insanity, in virtue of which our reactive attitudes are affected.
Origin
Late Middle English: from Old French nonage, from non- 'non-' + age 'age'.