How do I go back? I know this word (knonnichiwa) but accidentally put it in my dictionary thing.
Just click on the word and click the red X in the status bar to ignore the word or click the green tick mark to mark it as known so it gets added to your known words statistic.
Or click status 4 which means that you know the word. This way it is counted as a known word. If you follow Mark’s suggestion it is not counted as a known word.
if you knew the word, you would know it’s konnichiwa and not knonnichiwa