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"
a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer