The phrase "complete ignorance" means not knowing or understanding anything about a particular subject or situation. It refers to having absolutely no knowledge or awareness about something. Full definition
This is absolutely false, and demonstrates complete ignorance of pet food rules and regulations. (littlebigcat.com)
If you're going to live in complete ignorance, go all the way, I say. (religion.blogs.cnn.com)
Following that was complete ignorance about the history of the civil rights movement stemming from racist attitudes towards black bodies. (themarysue.com)