lacking in schooling; "untaught people whose verbal skills are grossly deficient"; "an untutored genius"; "uneducated children"
If someone is untutored, they have not been formally trained to do something, although they may be quite skilled at it. This untutored mathematician had an obsession with numbers They had left school at fifteen and were quite untutored in writing. not having been taught to do something to the untutored eye/ear/mind