uneducated in the fundamentals of a given art or branch of learning; lacking knowledge of a specific field; "she is ignorant of quantum mechanics"; "he is musically illiterate"
uneducated in general; lacking knowledge or sophistication; "an ignorant man"; "nescient of contemporary literature"; "an unlearned group incapable of understanding complex issues"; "exhibiting contempt for his unlettered companions"
unaware because of a lack of relevant information or knowledge; "he was completely ignorant of the circumstances"; "an unknowledgeable assistant"; "his rudeness was unwitting"
without preparation; not prepared for; "unprepared remarks"; "the shock was unprepared"; "our treaty makers approached their immensely difficult problems unprepared"- R.E.Danielson
(of persons or their actions) able or disposed to inflict pain or suffering; "a barbarous crime"; "brutal beatings"; "cruel tortures"; "Stalin's roughshod treatment of the kulaks"; "a savage slap"; "vicious kicks"