Lacking knowledge or awareness in general; uneducated or unsophisticated.
That is from the dictionary so she did use the word properly because the sales person was obviously lacking customer service knowledge. Don't try to be mean ane make someone else look dumb until you have done research.
It's not the fact that they lack knowledge its the fact she was being rude..please don't comment acting like your right..when clearly you're being ignorant to what we're talking about ...
#41 you failed horribly at proving your point. She used ignorant as many people misuse it, as rude. You actually supported the comment saying it was the incorrect use.
Actually #53 the initial commenter used it right and that explanation used by #41 is right too.
The cashier *lacks customer service knowledge* which makes him ignorant. You don't say out loud what you think about someone, it's rude but also *ignorant* because you should know better than to insult someone for no reason, even worse since she's a customer.