Uneducated (adjective)

1. Not having received an education; illiterate or semiliterate.
2. Lacking knowledge or understanding in a particular field.
3. Not having been educated about a particular subject.

Origin:

From un- (not) + educate (to provide with an education).

Examples:

1. An uneducated population.
2. His uneducated guess.
3. She is uneducated in finance.
4. An uneducated decision.
5. The uneducated masses.