The word ignorant, and I quote from Merriam-Webster Online, means:
Quote:
1 a: destitute of knowledge or education ; also : lacking knowledge or comprehension of the thing specified b: resulting from or showing lack of knowledge or intelligence
2: unaware, uninformed
— ig·no·rant·ly adverb
2: unaware, uninformed
— ig·no·rant·ly adverb
In other words, not knowing or not knowledgeable.
They seem to be confusing the word with "arrogant" which means to be full of one's self, pompous, or vain.